U.S. patent application number 17/553443 was filed with the patent office on 2022-04-07 for method for monitoring physical downlink control channel in wireless communication system, and device using method.
The applicant listed for this patent is LG Electronics Inc.. Invention is credited to Joonkui AHN, Seunggye HWANG, Changhwan PARK, Inkwon SEO.
Application Number | 20220110054 17/553443 |
Document ID | / |
Family ID | 1000006068318 |
Filed Date | 2022-04-07 |
View All Diagrams
United States Patent
Application |
20220110054 |
Kind Code |
A1 |
SEO; Inkwon ; et
al. |
April 7, 2022 |
METHOD FOR MONITORING PHYSICAL DOWNLINK CONTROL CHANNEL IN WIRELESS
COMMUNICATION SYSTEM, AND DEVICE USING METHOD
Abstract
A method by which a terminal monitors a physical downlink
control channel (PDCCH) in a wireless communication system, and a
device therefor are provided. In the method, a terminal wakes up in
a DRX cycle linked with a monitoring occasion so as to monitor a
PDCCH if a wake up signal (WUS) monitoring occasion does not exist
in a monitoring window for allowing the terminal to monitor the
WUS.
Inventors: |
SEO; Inkwon; (Seoul, KR)
; AHN; Joonkui; (Seoul, KR) ; PARK; Changhwan;
(Seoul, KR) ; HWANG; Seunggye; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Electronics Inc. |
Seoul |
|
KR |
|
|
Family ID: |
1000006068318 |
Appl. No.: |
17/553443 |
Filed: |
December 16, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/KR2020/009321 |
Jul 15, 2020 |
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17553443 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 52/0216 20130101;
H04W 52/0229 20130101 |
International
Class: |
H04W 52/02 20060101
H04W052/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2019 |
KR |
10-2019-0085219 |
Claims
1. A method of monitoring a physical downlink control channel
(PDCCH) by a user equipment (UE) in a wireless communication
system, the method comprising: receiving a configuration message
informing at least one monitoring occasion for detecting a wake up
signal (WUS); and based on the at least one monitoring occasion
being located before a predetermined time from a start time of a
next discontinuous reception (DRX)-on duration, monitoring the
PDCCH in the next DRX-on duration.
2. The method of claim 1, wherein the WUS is downlink control
information (DCI) including a wake-up indication.
3. The method of claim 1, wherein monitoring for the detection of
the WUS is performed based on the at least one monitoring occasion
being located within the predetermined time from the start time of
the next DRX-on duration.
4. The method of claim 1, wherein monitoring for the detection of
the WUS is not performed based on the at least one monitoring
occasion being located before the predetermined time from the start
time of the next DRX-on duration.
5. The method of claim 1, wherein the configuration message is a
high layer message for configuring a search space.
6. The method of claim 1, wherein the UE wakes up at the start time
of the next DRX-on duration based on the at least one monitoring
occasion being located before the predetermined time from the start
time of the next DRX-on duration.
7. The method of claim 1, further comprising: receiving a message
informing the predetermined time.
8. A user equipment (UE), comprising: a transceiver; and a
processor being operatively connected to the transceiver, wherein
the processor is configured to: receive a configuration message
informing at least one monitoring occasion for detecting a wake up
signal (WUS), and based on the at least one monitoring occasion
being located before a predetermined time from a start time of a
next discontinuous reception (DRX)-on duration, monitor the PDCCH
in the next DRX-on duration.
9. The UE of claim 8, wherein the WUS is downlink control
information (DCI) including a wake-up indication.
10. The UE of claim 8, wherein monitoring for the detection of the
WUS is performed based on the at least one monitoring occasion
being located within the predetermined time from the start time of
the next DRX-on duration.
11. The UE of claim 8, wherein monitoring for the detection of the
WUS is not performed based on the at least one monitoring occasion
being located before the predetermined time from the start time of
the next DRX-on duration.
12. The UE of claim 8, wherein the configuration message is a high
layer message for configuring a search space.
13. The UE of claim 8, wherein the UE wakes up at the start time of
the next DRX-on duration based on the at least one monitoring
occasion being located before the predetermined time from the start
time of the next DRX-on duration.
14. The UE of claim 8, wherein the processor is further configured
to receive a message informing the predetermined time.
15. An apparatus operating in a wireless communication system,
comprising: a processor; and a memory coupled with the processor,
wherein the processor is configured to: receive a configuration
message informing at least one monitoring occasion for detecting a
wake up signal (WUS); and based on the at least one monitoring
occasion being located before a predetermined time from a start
time of a next discontinuous reception (DRX)-on duration, monitor
the PDCCH in the next DRX-on duration.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Pursuant to 35 U.S.C. .sctn. 119(e), this application is a
continuation of International Application PCT/KR2020/009321, with
an international filing date of Jul. 15, 2020, which claims the
benefit of Korean Patent Application No. 10-2019-0085219, filed on
Jul. 15, 2019, the contents of which are hereby incorporated by
reference herein in their entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to a method of monitoring a
physical downlink control channel in a wireless communication
system, and an apparatus using the method.
RELATED ART
[0003] As more and more communication devices require more
communication capacity, there is a need for improved mobile
broadband communication over existing radio access technology.
Also, massive machine type communications (MTC), which provides
various services by connecting many devices and objects, is one of
the major issues to be considered in the next generation
communication. In addition, communication system design considering
reliability/latency sensitive service/UE is being discussed. The
introduction of next generation radio access technology considering
enhanced mobile broadband communication (eMBB), massive MTC (mMTC),
ultra-reliable and low latency communication (URLLC) is discussed.
This new technology may be called new radio access technology (new
RAT or NR) in the present disclosure for convenience. NR is also
called the fifth generation (5G) system.
[0004] The improvement in performance and functions of a user
equipment (UE) such as an increase in UE's display resolution,
display size, processors, memories, and applications results in an
increase in power consumption. It is important for the UE to reduce
power consumption since power supply may be limited to a battery.
This is also applied to a UE operating in NR.
[0005] One example for reducing power consumption of the UE
includes a discontinuous reception (DRX) operation. The UE may need
to monitor a physical downlink control channel (PDCCH) in every
subframe to know whether there is data to be received. Since the UE
does not always receive data in all subframes, such an operation
results in unnecessary significant battery consumption. DRX is an
operation for reducing the battery consumption. That is, the UE
wakes up with a period of a DRX cycle to monitor a control channel
(e.g., PDCCH) during a determined time (DRX on duration). If there
is no PDCCH detection during the time, the UE enters a sleeping
mode, i.e., a state in which a radio frequency (RF) transceiver is
turned off. In the presence of the PDCCH detection during the time,
a PDCCH monitoring time may be extended, and data transmission and
reception may be performed based on the detected PDCCH.
[0006] Meanwhile, an additional power consumption reduction method
may be introduced for such a DRX operation. For example, it may be
unnecessary or inefficient for the UE to wake up every DRX cycle to
monitor the PDCCH. To this end, the network may provide a signal
(let's call it a wake-up signal: WUS) including information related
to whether to wake up to the UE before the start of the DRX cycle,
the UE may monitor the WUS on WUS monitoring occasions within the
configured WUS monitoring window. The UE may perform an indicated
operation in the DRX cycle based on the detected WUS.
[0007] However, in some cases, in a situation in which the UE is
configured to monitor the WUS, a situation in which there is no WUS
monitoring occasion within the time window for monitoring the WUS
may also occur. In this case, ambiguity occurs between the UE and
the network because it is not stipulated as to how the UE should
operate, and unnecessary wake ups may occur or response latency may
increase.
SUMMARY OF THE DISCLOSURE
[0008] The present disclosure provides a method of monitoring a
physical downlink control channel in a wireless communication
system, and an apparatus using the method.
[0009] In an aspect, provided is a method for monitoring a PDCCH of
a UE in a wireless communication system. The method comprises
receiving a configuration message informing at least one monitoring
occasion for detecting a wake up signal (WUS) and monitoring the
PDCCH in a next discontinuous reception (DRX)-on duration based on
the at least one monitoring occasion being located before a
predetermined time from a start time of the next DRX-on
duration.
[0010] In another aspect, provided is a user equipment (UE)
comprising a transceiver for transmitting and receiving a radio
signal and a processor being operatively connected to the
transceiver. The processor is configured to receive a configuration
message informing at least one monitoring occasion for detecting a
wake up signal (WUS) and monitor a PDCCH in a next discontinuous
reception (DRX)-on duration based on the at least one monitoring
occasion being located before a predetermined time from a start
time of the next DRX-on duration.
[0011] In other aspects, provided is a method for transmitting a
PDCCH of a base station in a wireless communication system. The
method comprises transmitting a configuration message informing at
least one monitoring occasion for detecting a wake up signal (WUS)
and transmitting the PDCCH in a next discontinuous reception
(DRX)-on duration based on the at least one monitoring occasion
being located before a predetermined time from a start time of the
next DRX-on duration.
[0012] In other aspects, a base station is provided. The base
station comprises a transceiver for transmitting and receiving a
radio signal and a processor being operatively connected to the
transceiver. The processor is configured to transmit a
configuration message informing at least one monitoring occasion
for detecting a wake up signal (WUS) and transmit the PDCCH in a
next discontinuous reception (DRX)-on duration based on the at
least one monitoring occasion being located before a predetermined
time from a start time of the next DRX-on duration.
[0013] In other aspects, provided is at least one computer readable
medium (CRM) including instructions being executed by at least one
processor. The at least one processor is configured to receive a
configuration message informing at least one monitoring occasion
for detecting a wake up signal (WUS) and monitor a physical
downlink control channel (PDCCH) in a next discontinuous reception
(DRX)-on duration when the at least one monitoring occasion is
located before a predetermined time from a start time of the next
DRX-on duration.
[0014] In other aspects, provided is an apparatus operating in a
wireless communication system. The apparatus comprises a processor
and a memory coupled with the processor. The processor is
configured to receive a configuration message informing at least
one monitoring occasion for detecting a wake up signal (WUS) and
monitor a physical downlink control channel (PDCCH) in a next
discontinuous reception (DRX)-on duration when the at least one
monitoring occasion is located before a predetermined time from a
start time of the next DRX-on duration.
[0015] In a situation in which the UE is set to monitor WUS, if
there is no WUS monitoring occasion within the time window for
monitoring WUS, the UE operation is clearly defined. That is, the
UE wakes up in the next DRX on duration and performs PDCCH
monitoring (from the viewpoint of a timer, it may be expressed that
drx-onDurationTimer is started). Through this, even in the above
case, ambiguity does not occur between the UE and the network,
unnecessary waking of the UE does not occur, and occurrence of an
increase in response latency can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a wireless communication system to which the
present disclosure may be applied.
[0017] FIG. 2 is a diagram showing a wireless protocol architecture
for a user plane.
[0018] FIG. 3 is a diagram showing a wireless protocol architecture
for a control plane.
[0019] FIG. 4 illustrates a system structure of a next generation
radio access network (NG-RAN) to which NR is applied.
[0020] FIG. 5 illustrates a functional division between an NG-RAN
and a SGC.
[0021] FIG. 6 illustrates an example of a frame structure that may
be applied in NR.
[0022] FIG. 7 illustrates a slot structure of an NR frame.
[0023] FIG. 8 illustrates CORESET.
[0024] FIG. 9 is a diagram illustrating a difference between a
related art control region and the CORESET in NR.
[0025] FIG. 10 illustrates an example of a frame structure for new
radio access technology.
[0026] FIG. 11 illustrates a structure of a self-contained
slot.
[0027] FIG. 12 illustrates physical channels and typical signal
transmission.
[0028] FIG. 13 illustrates a scenario in which three different
bandwidth parts are configured.
[0029] FIG. 14 illustrates a DRX cycle.
[0030] FIG. 15 illustrates a WUS monitoring occasion.
[0031] FIGS. 16 and 17 illustrate a case in which an occasion for
WUS monitoring is located in the WUS monitoring window and a case
in which it is not.
[0032] FIG. 18 illustrates a PDCCH monitoring operation method of a
UE according to an embodiment of the present disclosure.
[0033] FIG. 19 shows a specific example to which FIG. 18 is
applied.
[0034] FIG. 20 shows an example of applying the method described in
FIGS. 18 and 19 between a network and a UE.
[0035] FIG. 21 illustrates a wireless device applicable to the
present specification.
[0036] FIG. 22 shows an example of a structure of a signal
processing module.
[0037] FIG. 23 shows another example of a structure of a signal
processing module in a transmitting device.
[0038] FIG. 24 illustrates an example of a wireless communication
device for implementing the present disclosure.
[0039] FIG. 25 shows an example of a processor 2000.
[0040] FIG. 26 shows an example of a processor 3000.
[0041] FIG. 27 shows another example of a wireless device.
[0042] FIG. 28 shows another example of a wireless device applied
to the present specification.
[0043] FIG. 29 illustrates a hand-held device applied to the
present specification.
[0044] FIG. 30 illustrates a communication system 1 applied to the
present specification.
[0045] FIG. 31 illustrates a vehicle or an autonomous vehicle
applicable to the present specification.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0046] FIG. 1 shows a wireless communication system to which the
present disclosure may be applied. The wireless communication
system may be referred to as an Evolved-UMTS Terrestrial Radio
Access Network (E-UTRAN) or a Long Term Evolution (LTE)/LTE-A
system.
[0047] The E-UTRAN includes at least one base station (BS) 20 which
provides a control plane and a user plane to a user equipment (UE)
10. The UE 10 may be fixed or mobile, and may be referred to as
another terminology, such as a mobile station (MS), a user terminal
(UT), a subscriber station (SS), a mobile terminal (MT), a wireless
device, terminal, etc. The BS 20 is generally a fixed station that
communicates with the UE 10 and may be referred to as another
terminology, such as an evolved node-B (eNB), a base transceiver
system (BTS), an access point, gNB, etc.
[0048] The BSs 20 are interconnected by means of an X2 interface.
The BSs 20 are also connected by means of an S1 interface to an
evolved packet core (EPC) 30, more specifically, to a mobility
management entity (MME) through S1-MME and to a serving gateway
(S-GW) through S1-U.
[0049] The EPC 30 includes an MME, an S-GW, and a packet data
network-gateway (P-GW). The MME has access information of the UE or
capability information of the UE, and such information is generally
used for mobility management of the UE. The S-GW is a gateway
having an E-UTRAN as an end point. The P-GW is a gateway having a
PDN as an end point.
[0050] Layers of a radio interface protocol between the UE and the
network can be classified into a first layer (L1), a second layer
(L2), and a third layer (L3) based on the lower three layers of the
open system interconnection (OSI) model that is well-known in the
communication system. Among them, a physical (PHY) layer belonging
to the first layer provides an information transfer service by
using a physical channel, and a radio resource control (RRC) layer
belonging to the third layer serves to control a radio resource
between the UE and the network. For this, the RRC layer exchanges
an RRC message between the UE and the BS.
[0051] FIG. 2 is a diagram showing a wireless protocol architecture
for a user plane. FIG. 3 is a diagram showing a wireless protocol
architecture for a control plane. The user plane is a protocol
stack for user data transmission. The control plane is a protocol
stack for control signal transmission.
[0052] Referring to FIGS. 2 and 3, a PHY layer provides an upper
layer(=higher layer) with an information transfer service through a
physical channel The PHY layer is connected to a medium access
control (MAC) layer which is an upper layer of the PHY layer
through a transport channel Data is transferred between the MAC
layer and the PHY layer through the transport channel The transport
channel is classified according to how and with what
characteristics data is transferred through a radio interface.
[0053] Data is moved between different PHY layers, that is, the PHY
layers of a transmitter and a receiver, through a physical channel
The physical channel may be modulated according to an Orthogonal
Frequency Division Multiplexing (OFDM) scheme, and use the time and
frequency as radio resources.
[0054] The functions of the MAC layer include mapping between a
logical channel and a transport channel and multiplexing and
demultiplexing to a transport block that is provided through a
physical channel on the transport channel of a MAC Service Data
Unit (SDU) that belongs to a logical channel The MAC layer provides
service to a Radio Link Control (RLC) layer through the logical
channel
[0055] The functions of the RLC layer include the concatenation,
segmentation, and reassembly of an RLC SDU. In order to guarantee
various types of Quality of Service (QoS) required by a Radio
Bearer (RB), the RLC layer provides three types of operation mode:
Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged
Mode (AM). AM RLC provides error correction through an Automatic
Repeat Request (ARQ).
[0056] The RRC layer is defined only on the control plane. The RRC
layer is related to the configuration, reconfiguration, and release
of radio bearers, and is responsible for control of logical
channels, transport channels, and PHY channels. An RB means a
logical route that is provided by the first layer (PHY layer) and
the second layers (MAC layer, the RLC layer, and the PDCP layer) in
order to transfer data between UE and a network.
[0057] The function of a Packet Data Convergence Protocol (PDCP)
layer on the user plane includes the transfer of user data and
header compression and ciphering. The function of the PDCP layer on
the user plane further includes the transfer and
encryption/integrity protection of control plane data.
[0058] What an RB is configured means a process of defining the
characteristics of a wireless protocol layer and channels in order
to provide specific service and configuring each detailed parameter
and operating method. An RB can be divided into two types of a
Signaling RB (SRB) and a Data RB (DRB). The SRB is used as a
passage through which an RRC message is transmitted on the control
plane, and the DRB is used as a passage through which user data is
transmitted on the user plane.
[0059] If RRC connection is established between the RRC layer of UE
and the RRC layer of an E-UTRAN, the UE is in the RRC connected
state. If not, the UE is in the RRC idle state.
[0060] A downlink transport channel through which data is
transmitted from a network to UE includes a broadcast channel (BCH)
through which system information is transmitted and a downlink
shared channel (SCH) through which user traffic or control messages
are transmitted. Traffic or a control message for downlink
multicast or broadcast service may be transmitted through the
downlink SCH, or may be transmitted through an additional downlink
multicast channel (MCH). Meanwhile, an uplink transport channel
through which data is transmitted from UE to a network includes a
random access channel (RACH) through which an initial control
message is transmitted and an uplink shared channel (SCH) through
which user traffic or control messages are transmitted.
[0061] Logical channels that are placed over the transport channel
and that are mapped to the transport channel include a broadcast
control channel (BCCH), a paging control channel (PCCH), a common
control channel (CCCH), a multicast control channel (MCCH), and a
multicast traffic channel (MTCH).
[0062] The physical channel includes several OFDM symbols in the
time domain and several subcarriers in the frequency domain. One
subframe includes a plurality of OFDM symbols in the time domain.
An RB is a resources allocation unit, and includes a plurality of
OFDM symbols and a plurality of subcarriers. Furthermore, each
subframe may use specific subcarriers of specific OFDM symbols
(e.g., the first OFDM symbol) of the corresponding subframe for a
physical downlink control channel (PDCCH), that is, an L1/L2
control channel A Transmission Time Interval (TTI) is a unit time
for subframe transmission.
[0063] Hereinafter, a new radio access technology (new RAT, NR)
will be described.
[0064] As more and more communication devices require more
communication capacity, there is a need for improved mobile
broadband communication over existing radio access technology.
Also, massive machine type communications (MTC), which provides
various services by connecting many devices and objects, is one of
the major issues to be considered in the next generation
communication. In addition, communication system design considering
reliability/latency sensitive service/UE is being discussed. The
introduction of next generation radio access technology considering
enhanced mobile broadband communication (eMBB), massive MTC (mMTC),
ultrareliable and low latency communication (URLLC) is discussed.
This new technology may be called new radio access technology (new
RAT or NR) in the present disclosure for convenience.
[0065] FIG. 4 illustrates a system structure of a next generation
radio access network (NG-RAN) to which NR is applied.
[0066] Referring to FIG. 4, the NG-RAN may include a gNB and/or an
eNB that provides user plane and control plane protocol termination
to a UE. FIG. 4 illustrates the case of including only gNBs. The
gNB and the eNB are connected by an Xn interface. The gNB and the
eNB are connected to a 5G core network (5GC) via an NG interface.
More specifically, the gNB and the eNB are connected to an access
and mobility management function (AMF) via an NG-C interface and
connected to a user plane function (UPF) via an NG-U interface.
[0067] FIG. 5 illustrates a functional division between an NG-RAN
and a 5GC.
[0068] Referring to FIG. 5, the gNB may provide functions such as
an inter-cell radio resource management (Inter Cell RRM), radio
bearer management (RB control), connection mobility control, radio
admission control, measurement configuration & provision,
dynamic resource allocation, and the like. The AMF may provide
functions such as NAS security, idle state mobility handling, and
so on. The UPF may provide functions such as mobility anchoring,
PDU processing, and the like. The SMF may provide functions such as
UE IP address assignment, PDU session control, and so on.
[0069] FIG. 6 illustrates an example of a frame structure that may
be applied in NR.
[0070] Referring to FIG. 6, in the NR, a radio frame (hereinafter,
also referred to as a frame) may be used in uplink and downlink
transmissions. The frame has a length of 10 ms, and may be defined
as two 5 ms half-frames (HFs). The HF may be defined as five 1 ms
subframes (SFs). The SF may be divided into one or more slots, and
the number of slots within the SF depends on a subcarrier spacing
(SCS). Each slot includes 12 or 14 OFDM(A) symbols according to a
cyclic prefix (CP). In case of using a normal CP, each slot
includes 14 symbols. In case of using an extended CP, each slot
includes 12 symbols. Herein, a symbol may include an OFDM symbol
(or CP-OFDM symbol) and a Single Carrier-FDMA (SC-FDMA) symbol (or
Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbol).
[0071] The following table 1 illustrates a subcarrier spacing
configuration .mu..
TABLE-US-00001 TABLE 1 .mu. .DELTA.f = 2.sup..mu. 15[kHz] Cyclic
prefix 0 15 Normal 1 30 Normal 2 60 Normal Extended 3 120 normal 4
240 normal
[0072] The following table 2 illustrates the number of slots in a
frame (N.sup.frame, .mu..sub.slot), the number of slots in a
subframe (N.sup.subframe, .mu..sub.slot), the number of symbols in
a slot (N.sup.slot.sub.symb), and the like, according to subcarrier
spacing configurations .mu..
TABLE-US-00002 TABLE 2 .mu. N.sub.symb.sup.slot
N.sub.slot.sup.frame, .mu. N.sub.slot.sup.subframe, .mu. 0 14 10 1
1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16
[0073] FIG. 6 illustrates a case of .mu.=0, 1, 2, 3.
[0074] Table 2-1 below illustrates that the number of symbols per
slot, the number of slots per frame, and the number of slots per
subframe vary depending on the SCS, in case of using an extended CP
(.mu.=2, 60 KHz).
TABLE-US-00003 TABLE 2-1 .mu. N.sup.slot.sub.symb N.sup.frame,
.mu..sub.slot N.sup.subframe, .mu..sub.slot 2 12 40 4
[0075] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length,
and so on) may be differently configured between a plurality of
cells integrated to one UE. Accordingly, an (absolute time)
duration of a time resource (e.g., SF, slot or TTI) (for
convenience, collectively referred to as a time unit (TU))
configured of the same number of symbols may be differently
configured between the integrated cells.
[0076] FIG. 7 illustrates a slot structure of an NR frame.
[0077] A slot may include a plurality of symbols in a time domain.
For example, in case of a normal CP, one slot may include 7
symbols. However, in case of an extended CP, one slot may include 6
symbols. A carrier may include a plurality of subcarriers in a
frequency domain. A resource block (RB) may be defined as a
plurality of consecutive subcarriers (e.g., 12 subcarriers) in the
frequency domain. A bandwidth part (BWP) may be defined as a
plurality of consecutive (physical) resource blocks ((P)RBs) in the
frequency domain, and the BWP may correspond to one numerology
(e.g., SCS, CP length, and so on). The carrier may include up to N
(e.g., 5) BWPs. Data communication may be performed via an
activated BWP, and only one BWP may be activated for one UE. In a
resource grid, each element may be referred to as a resource
element (RE), and one complex symbol may be mapped thereto.
[0078] A physical downlink control channel (PDCCH) may include one
or more control channel elements (CCEs) as illustrated in the
following table 3.
TABLE-US-00004 TABLE 3 Aggregation level Number of CCEs 1 1 2 2 4 4
8 8 16 16
[0079] That is, the PDCCH may be transmitted through a resource
including 1, 2, 4, 8, or 16 CCEs. Here, the CCE includes six
resource element groups (REGs), and one REG includes one resource
block in a frequency domain and one orthogonal frequency division
multiplexing (OFDM) symbol in a time domain.
[0080] Monitoring implies decoding of each PDCCH candidate
according to a downlink control information (DCI) format. The UE
monitors a set of PDCCH candidates in one or more CORESETs (to be
described below) on an active DL BWP of each activated serving cell
in which PDCCH monitoring is configured, according to a
corresponding search space set.
[0081] A new unit called a control resource set (CORESET) may be
introduced in the NR. The UE may receive a PDCCH in the
CORESET.
[0082] FIG. 8 illustrates CORESET.
[0083] Referring to FIG. 8, the CORESET includes
N.sup.CORESET.sub.RB number of resource blocks in the frequency
domain, and N.sup.CORESET.sub.symb .di-elect cons. {1, 2, 3} number
of symbols in the time domain. N.sup.CORESET.sub.RB and
N.sup.CORESET.sub.symb may be provided by a base station via higher
layer signaling. As illustrated in FIG. 8, a plurality of CCEs (or
REGs) may be included in the CORESET. One CCE may be composed of a
plurality of resource element groups (REGs), and one REG may
include one OFDM symbol in the time domain and 12 resource elements
in the frequency domain.
[0084] The UE may attempt to detect a PDCCH in units of 1, 2, 4, 8,
or 16 CCEs in the CORESET. One or a plurality of CCEs in which
PDCCH detection may be attempted may be referred to as PDCCH
candidates.
[0085] A plurality of CORESETs may be configured for the UE.
[0086] FIG. 9 is a diagram illustrating a difference between a
related art control region and the CORESET in NR.
[0087] Referring to FIG. 9, a control region 800 in the related art
wireless communication system (e.g., LTE/LTE-A) is configured over
the entire system band used by a base station (BS). All the UEs,
excluding some (e.g., eMTC/NB-IoT UE) supporting only a narrow
band, must be able to receive wireless signals of the entire system
band of the BS in order to properly receive/decode control
information transmitted by the BS.
[0088] On the other hand, in NR, CORESET described above was
introduced. CORESETs 801, 802, and 803 are radio resources for
control information to be received by the UE and may use only a
portion, rather than the entirety of the system bandwidth. The BS
may allocate the CORESET to each UE and may transmit control
information through the allocated CORESET. For example, in FIG. 9,
a first CORESET 801 may be allocated to UE 1, a second CORESET 802
may be allocated to UE 2, and a third CORESET 803 may be allocated
to UE 3. In the NR, the UE may receive control information from the
BS, without necessarily receiving the entire system band.
[0089] The CORESET may include a UE-specific CORESET for
transmitting UE-specific control information and a common CORESET
for transmitting control information common to all UEs.
[0090] Meanwhile, NR may require high reliability according to
applications. In such a situation, a target block error rate (BLER)
for downlink control information (DCI) transmitted through a
downlink control channel (e.g., physical downlink control channel
(PDCCH)) may remarkably decrease compared to those of conventional
technologies. As an example of a method for satisfying requirement
that requires high reliability, content included in DCI can be
reduced and/or the amount of resources used for DCI transmission
can be increased. Here, resources can include at least one of
resources in the time domain, resources in the frequency domain,
resources in the code domain and resources in the spatial
domain.
[0091] In NR, the following technologies/features can be
applied.
[0092] <Self-Contained Subframe Structure>
[0093] FIG. 10 illustrates an example of a frame structure for new
radio access technology.
[0094] In NR, a structure in which a control channel and a data
channel are time-division-multiplexed within one TTI, as shown in
FIG. 10, can be considered as a frame structure in order to
minimize latency.
[0095] In FIG. 10, a shaded region represents a downlink control
region and a black region represents an uplink control region. The
remaining region may be used for downlink (DL) data transmission or
uplink (UL) data transmission. This structure is characterized in
that DL transmission and UL transmission are sequentially performed
within one subframe and thus DL data can be transmitted and UL
ACK/NACK can be received within the subframe. Consequently, a time
required from occurrence of a data transmission error to data
retransmission is reduced, thereby minimizing latency in final data
transmission.
[0096] In this data and control TDMed subframe structure, a time
gap for a base station and a UE to switch from a transmission mode
to a reception mode or from the reception mode to the transmission
mode may be required. To this end, some OFDM symbols at a time when
DL switches to UL may be set to a guard period (GP) in the
self-contained subframe structure.
[0097] FIG. 11 illustrates a structure of a self-contained
slot.
[0098] In an NR system, a DL control channel, DL or UL data, a UL
control channel, and the like may be contained in one slot. For
example, first N symbols (hereinafter, DL control region) in the
slot may be used to transmit a DL control channel, and last M
symbols (hereinafter, UL control region) in the slot may be used to
transmit a UL control channel. N and M are integers greater than or
equal to 0. A resource region (hereinafter, a data region) which
exists between the DL control region and the UL control region may
be used for DL data transmission or UL data transmission. For
example, the following configuration may be considered. Respective
durations are listed in a temporal order.
[0099] 1. DL only configuration
[0100] 2. UL only configuration
[0101] 3. Mixed UL-DL configuration [0102] DL region+Guard period
(GP)+UL control region [0103] DL control region+GP+UL region
[0104] DL region: (i) DL data region, (ii) DL control region+DL
data region
[0105] UL region: (i) UL data region, (ii) UL data region+UL
control region
[0106] A PDCCH may be transmitted in the DL control region, and a
physical downlink shared channel (PDSCH) may be transmitted in the
DL data region. A physical uplink control channel (PUCCH) may be
transmitted in the UL control region, and a physical uplink shared
channel (PUSCH) may be transmitted in the UL data region. Downlink
control information (DCI), for example, DL data scheduling
information, UL data scheduling information, and the like, may be
transmitted on the PDCCH. Uplink control information (UCI), for
example, ACK/NACK information about DL data, channel state
information (CSI), and a scheduling request (SR), may be
transmitted on the PUCCH. A GP provides a time gap in a process in
which a BS and a UE switch from a TX mode to an RX mode or a
process in which the BS and the UE switch from the RX mode to the
TX mode. Some symbols at the time of switching from DL to UL within
a subframe may be configured as the GP.
[0107] <Analog Beamforming #1>
[0108] Wavelengths are shortened in millimeter wave (mmW) and thus
a large number of antenna elements can be installed in the same
area. That is, the wavelength is 1 cm at 30 GHz and thus a total of
100 antenna elements can be installed in the form of a
2-dimensional array at an interval of 0.5 lambda (wavelength) in a
panel of 5.times.5 cm. Accordingly, it is possible to increase a
beamforming (BF) gain using a large number of antenna elements to
increase coverage or improve throughput in mmW.
[0109] In this case, if a transceiver unit (TXRU) is provided to
adjust transmission power and phase per antenna element,
independent beamforming per frequency resource can be performed.
However, installation of TXRUs for all of about 100 antenna
elements decreases effectiveness in terms of cost. Accordingly, a
method of mapping a large number of antenna elements to one TXRU
and controlling a beam direction using an analog phase shifter is
considered. Such analog beamforming can form only one beam
direction in all bands and thus cannot provide frequency selective
beamforming.
[0110] Hybrid beamforming (BF) having a number B of TXRUs which is
smaller than Q antenna elements can be considered as an
intermediate form of digital BF and analog BF. In this case, the
number of directions of beams which can be simultaneously
transmitted are limited to B although it depends on a method of
connecting the B TXRUs and the Q antenna elements.
[0111] <Analog Beamforming #2>
[0112] When a plurality of antennas is used in NR, hybrid
beamforming which is a combination of digital beamforming and
analog beamforming is emerging. Here, in analog beamforming (or RF
beamforming) an RF end performs precoding (or combining) and thus
it is possible to achieve the performance similar to digital
beamforming while reducing the number of RF chains and the number
of D/A (or A/D) converters. For convenience, the hybrid beamforming
structure may be represented by N TXRUs and M physical antennas.
Then, the digital beamforming for the L data layers to be
transmitted at the transmitting end may be represented by an N by L
matrix, and the converted N digital signals are converted into
analog signals via TXRUs, and analog beamforming represented by an
M by N matrix is applied.
[0113] System information of the NR system may be transmitted in a
broadcasting manner. In this case, in one symbol, analog beams
belonging to different antenna panels may be simultaneously
transmitted. A scheme of introducing a beam RS (BRS) which is a
reference signal (RS) transmitted by applying a single analog beam
(corresponding to a specific antenna panel) is under discussion to
measure a channel per analog beam. The BRS may be defined for a
plurality of antenna ports, and each antenna port of the BRS may
correspond to a single analog beam. In this case, unlike the BRS, a
synchronization signal or an xPBCH may be transmitted by applying
all analog beams within an analog beam group so as to be correctly
received by any UE.
[0114] In the NR, in a time domain, a synchronization signal block
(SSB, or also referred to as a synchronization signal and physical
broadcast channel (SS/PBCH)) may consist of 4 OFDM symbols indexed
from 0 to 3 in an ascending order within a synchronization signal
block, and a PBCH associated with a primary synchronization signal
(PSS), secondary synchronization signal (SSS), and demodulation
reference signal (DMRS) may be mapped to the symbols. As described
above, the synchronization signal block may also be represented by
an SS/PBCH block.
[0115] In NR, since a plurality of synchronization signal blocks
(SSBs) may be transmitted at different times, respectively, and the
SSB may be used for performing initial access (IA), serving cell
measurement, and the like, it is preferable to transmit the SSB
first when transmission time and resources of the SSB overlap with
those of other signals. To this purpose, the network may broadcast
the transmission time and resource information of the SSB or
indicate them through UE-specific RRC signaling.
[0116] In NR, beams may be used for transmission and reception. If
reception performance of a current serving beam is degraded, a
process of searching for a new beam through the so-called Beam
Failure Recovery (BFR) may be performed.
[0117] Since the BFR process is not intended for declaring an error
or failure of a link between the network and a UE, it may be
assumed that a connection to the current serving cell is retained
even if the BFR process is performed. During the BFR process,
measurement of different beams (which may be expressed in terms of
CSI-RS port or Synchronization Signal Block (SSB) index) configured
by the network may be performed, and the best beam for the
corresponding UE may be selected. The UE may perform the BFR
process in a way that it performs an RACH process associated with a
beam yielding a good measurement result.
[0118] Now, a transmission configuration indicator (hereinafter,
TCI) state will be described. The TCI state may be configured for
each CORESET of a control channel, and may determine a parameter
for determining an RX beam of the UE, based on the TCI state.
[0119] For each DL BWP of a serving cell, a UE may be configured
for three or fewer CORESETs. Also, a UE may receive the following
information for each CORESET.
[0120] 1) CORESET index p (one of 0 to 11, where index of each
CORESET may be determined uniquely among BWPs of one serving
cell),
[0121] 2) PDCCH DM-RS scrambling sequence initialization value,
[0122] 3) Duration of a CORESET in the time domain (which may be
given in symbol units),
[0123] 4) Resource block set,
[0124] 5) CCE-to-REG mapping parameter,
[0125] 6) Antenna port quasi co-location indicating quasi
co-location (QCL) information of a DM-RS antenna port for receiving
a PDCCH in each CORESET (from a set of antenna port quasi
co-locations provided by a higher layer parameter called
`TCI-State`),
[0126] 7) Indication of presence of Transmission Configuration
Indication (TCI) field for a specific DCI format transmitted by the
PDCCH in the CORESET, and so on.
[0127] QCL will be described. If a characteristic of a channel
through which a symbol on one antenna port is conveyed can be
inferred from a characteristic of a channel through which a symbol
on the other antenna port is conveyed, the two antenna ports are
said to be quasi co-located (QCLed). For example, when two signals
A and B are transmitted from the same transmission antenna array to
which the same/similar spatial filter is applied, the two signals
may go through the same/similar channel state. From a perspective
of a receiver, upon receiving one of the two signals, another
signal may be detected by using a channel characteristic of the
received signal.
[0128] In this sense, when it is said that the signals A and B are
quasi co-located (QCLed), it may mean that the signals A and B have
went through a similar channel condition, and thus channel
information estimated to detect the signal A is also useful to
detect the signal B. Herein, the channel condition may be defined
according to, for example, a Doppler shift, a Doppler spread, an
average delay, a delay spread, a spatial reception parameter, or
the like.
[0129] A `TCI-State` parameter associates one or two downlink
reference signals to corresponding QCL types (QCL types A, B, C,
and D, see Table 4).
TABLE-US-00005 TABLE 4 QCL Type Description QCL-TypeA Doppler
shift, Doppler spread, Average delay, Delay spread QCL-TypeB
Doppler shift, Doppler spread' QCL-TypeC Doppler shift, Average
delay QCL-TypeD Spatial Rx parameter
[0130] Each `TCI-State` may include a parameter for configuring a
QCL relation between one or two downlink reference signals and a
DM-RS port of a PDSCH (or PDDCH) or a CSI-RS port of a CSI-RS
resource.
[0131] Meanwhile, for each DL BWP configured to a UE in one serving
cell, the UE may be provided with 10 (or less) search space sets.
For each search space set, the UE may be provided with at least one
of the following information.
[0132] 1) search space set index s (0.ltoreq.s<40), 2) an
association between a CORESET p and the search space set s, 3) a
PDCCH monitoring periodicity and a PDCCH monitoring offset (slot
unit), 4) a PDCCH monitoring pattern within a slot (e.g.,
indicating a first symbol of a CORSET in a slot for PDCCH
monitoring), 5) the number of slots in which the search space set s
exists, 6) the number of PDCCH candidates per CCE aggregation
level, 7) information indicating whether the search space set s is
CSS or USS.
[0133] In the NR, a CORESET#0 may be configured by a PBCH (or a
UE-dedicated signaling for handover or a PSCell configuration or a
BWP configuration). A search space (SS) set#0 configured by the
PBCH may have monitoring offsets (e.g., a slot offset, a symbol
offset) different for each associated SSB. This may be required to
minimize a search space occasion to be monitored by the UE.
Alternatively, this may be required to provide a beam sweeping
control/data region capable of performing control/data transmission
based on each beam so that communication with the UE is
persistently performed in a situation where a best beam of the UE
changes dynamically.
[0134] FIG. 12 illustrates physical channels and typical signal
transmission.
[0135] Referring to FIG. 12, in a wireless communication system, a
UE receives information from a BS through a downlink (DL), and the
UE transmits information to the BS through an uplink (UL). The
information transmitted/received by the BS and the UE includes data
and a variety of control information, and there are various
physical channels according to a type/purpose of the information
transmitted/received by the BS and the UE.
[0136] The UE which is powered on again in a power-off state or
which newly enters a cell performs an initial cell search operation
such as adjusting synchronization with the BS or the like (S11). To
this end, the UE receives a primary synchronization channel (PSCH)
and a secondary synchronization channel (SSCH) from the BS to
adjust synchronization with the BS, and acquire information such as
a cell identity (ID) or the like. In addition, the UE may receive a
physical broadcast channel (PBCH) from the BS to acquire
broadcasting information in the cell. In addition, the UE may
receive a downlink reference signal (DL RS) in an initial cell
search step to identify a downlink channel state.
[0137] Upon completing the initial cell search, the UE may receive
a physical downlink control channel (PDCCH) and a physical downlink
control channel (PDSCH) corresponding thereto to acquire more
specific system information (S12).
[0138] Thereafter, the UE may perform a random access procedure to
complete an access to the BS (S13.about.S16). Specifically, the UE
may transmit a preamble through a physical random access channel
(PRACH) (S13), and may receive a random access response (RAR) for
the preamble through a PDCCH and a PDSCH corresponding thereto
(S14). Thereafter, the UE may transmit a physical uplink shared
channel (PUSCH) by using scheduling information in the RAR (S15),
and may perform a contention resolution procedure similarly to the
PDCCH and the PDSCH corresponding thereto (S16).
[0139] After performing the aforementioned procedure, the UE may
perform PDCCH/PDSCH reception (S17) and PUSCH/physical uplink
control channel (PUCCH) transmission (S18) as a typical
uplink/downlink signal transmission procedure. Control information
transmitted by the UE to the BS is referred to as uplink control
information (UCI). The UCI includes hybrid automatic repeat and
request (HARQ) acknowledgement (ACK)/negative-ACK (HACK),
scheduling request (SR), channel state information (CSI), or the
like. The CSI includes a channel quality indicator (CQI), a
precoding matrix indicator (PMI), a rank indication (RI), or the
like. In general, the UCI is transmitted through the PUCCH.
However, when control information and data are to be transmitted
simultaneously, the UCI may be transmitted through the PUSCH. In
addition, the UE may aperiodically transmit the UCI through the
PUSCH according to a request/instruction of a network.
[0140] In order to enable reasonable battery consumption when
bandwidth adaptation (BA) is configured, only one uplink BWP and
one downlink BWP or only one downlink/uplink BWP pair for each
uplink carrier may be activated at once in an active serving cell,
and all other BWPs configured in the UE are deactivated. In the
deactivated BWPs, the UE does not monitor the PDCCH, and does not
perform transmission on the PUCCH, PRACH, and UL-SCH.
[0141] For the BA, RX and TX bandwidths of the UE are not
necessarily as wide as a bandwidth of a cell, and may be adjusted.
That is, it may be commanded such that a width is changed (e.g.,
reduced for a period of low activity for power saving), a position
in a frequency domain is moved (e.g., to increase scheduling
flexibility), and a subcarrier spacing is changed (e.g., to allow
different services). A subset of the entire cell bandwidth of a
cell is referred to as a bandwidth part (BWP), and the BA is
acquired by configuring BWP(s) to the UE and by notifying the UE
about a currently active BWP among configured BWPs. When the BA is
configured, the UE only needs to monitor the PDCCH on one active
BWP. That is, there is no need to monitor the PDCCH on the entire
downlink frequency of the cell. A BWP inactive timer (independent
of the aforementioned DRX inactive timer) is used to switch an
active BWP to a default BWP. That is, the timer restarts when PDCCH
decoding is successful, and switching to the default BWP occurs
when the timer expires.
[0142] FIG. 13 illustrates a scenario in which three different
bandwidth parts are configured.
[0143] FIG. 13 shows an example in which BWP.sub.1, BWP.sub.2, and
BWP.sub.3 are configured on a time-frequency resource. The
BWP.sub.1 may have a width of 40 MHz and a subcarrier spacing of 15
kHz. The BWP.sub.2 may have a width of 10 MHz and a subcarrier
spacing of 15 kHz. The BWP.sub.3 may have a width of 20 MHz and a
subcarrier spacing of 60 kHz. In other words, each BWP may have a
different width and/or a different subcarrier spacing.
[0144] Discontinuous reception (DRX) will now be described.
[0145] FIG. 14 illustrates a DRX cycle.
[0146] Referring to FIG. 14, the DRX cycle may consist of `On
Duration (on-duration, hereinafter may also be referred to as DRX
on-duration)` and `Opportunity for DRX`. The DRX cycle defines a
time interval in which the on-duration is cyclically repeated. The
on-duration indicates a time duration in which a UE performs
monitoring to receive a PDCCH. If DRX is configured, the UE
performs PDCCH monitoring during the `on-duration`. If there is a
PDCCH successfully detected during the PDCCH monitoring, the UE
operates an inactivity timer and maintains an awake state. On the
other hand, if there is no PDCCH successfully detected during the
PDCCH monitoring, the UE enters a sleep state after the
`on-duration` ends.
[0147] Table 5 shows a UE procedure related to DRX (RRC_CONNECTED
state). Referring to Table 5, DRX configuration information may be
received through higher layer (e.g., RRC) signaling. Whether DRX is
ON or OFF may be controlled by a DRX command of a MAC layer. If the
DRX is configured, PDCCH monitoring may be performed
discontinuously.
TABLE-US-00006 TABLE 5 Type of signals UE procedure 1.sup.st step
RRC signalling Receive DRX configuration (MAC-CellGroupConfig)
information 2.sup.nd step MAC CE Receive DRX command ((Long) DRX
command MAC CE) 3.sup.rd step -- Monitor a PDCCH during an
on-duration of a DRX cycle
[0148] MAC-CellGroupConfig may include configuration information
required to configure a medium access control (MAC) parameter for a
cell group. MAC-CellGroupConfig may also include configuration
information regarding DRX. For example, MAC-CellGroupConfig may
include information for defining DRX as follows. [0149] Value of
drx-OnDurationTimer: This defines a length of a duration at the
beginning of a DRX cycle. [0150] Value of drx-InactivityTimer: This
defines a length of a time duration in which the UE is in an awake
state, after a PDCCH occasion in which a PDCCH indicating initial
UL or DL data is detected. [0151] Value of drx-HARQ-RTT-TimerDL:
This defines a length of a maximum time duration until DL
retransmission is received, after DL initial transmission is
received. [0152] Value of drx-HARQ-RTT-TimerUL: This defines a
length of a maximum time duration until a grant for UL
retransmission is received, after a grant for UL initial
transmission is received. [0153] drx-LongCycleStartOffset: This
defines a time length and a starting point of a DRX cycle [0154]
drx-ShortCycle (optional): This defines a time length of a short
DRX cycle.
[0155] Herein, if any one of drx-OnDurationTimer,
drx-InactivityTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerUL
is operating, the UE performs PDCCH monitoring in every PDCCH
occasion while maintaining an awake state.
[0156] The UE may know a starting point of a DRX cycle, a duration
(duration time) of the DRX cycle, a starting point of an
on-duration timer, and a duration of the on-duration timer
according to a DRX configuration. Thereafter, the UE attempts
reception/detection for scheduling information (i.e., PDCCH) within
the on-duration of each DRX cycle (this may be represented that
scheduling information is monitored).
[0157] If the scheduling information (PDCCH) is detected within the
on-duration of the DRX cycle (DRX-on duration), an inactivity timer
is activated, and detection is attempted for another scheduling
information during a given inactivity timer duration (a time
duration in which the inactivity timer runs). In this case, the
on-duration and the inactivity timer duration in which the UE
performs the signal reception/detection operation may be together
referred to as an active time. If the scheduling information is not
detected in the on-duration, only the on-duration may be the active
time.
[0158] When the inactivity timer ends without reception/detection
of an additional signal (a control signal or data), the UE does not
perform scheduling information and corresponding DL reception/UL
transmission until an on-duration of a next DRX cycle (a DRX on
duration) starts after the inactivity timer ends.
[0159] A duration adjustment of a DRX cycle, a duration adjustment
of an on-duration timer/inactivity timer, or the like plays an
important role in determining whether the UE sleeps. According to
the setting for a corresponding parameter, the network may
configure the UE to frequently sleep or continuously perform
monitoring on the scheduling information. This may act as an
element for determining whether power saving of the UE will be
achieved.
[0160] Now, the present disclosure will be described.
[0161] The present disclosure proposes a method of determining an
occasion (time point) for monitoring a DCI (or signal) indicating
wake up (or go-to-sleep), considerations in the corresponding
process, and a UE operation.
[0162] In NR, a wake up signal (WUS) may be introduced to save
power of the UE. The WUS may indicate, for example, whether to
perform PDCCH monitoring in a DRX on-duration in connection with a
DRX operation (or DRX cycle).
[0163] WUS may be provided in the form of DCI. A new DCI for WUS
(which may also be referred to as WUS DCI) may be considered, and a
WUS monitoring occasion (time point, hereinafter the same) for
performing WUS monitoring needs to be defined. When the WUS is
provided in DCI (e.g., DCI format 2_6), the DCI may be transmitted
through a PDCCH, and the DCI may be referred to as a WUS DCI. In
this case, WUS monitoring is an expression equivalent to PDCCH
monitoring for detection of the DCI. A PDCCH including the DCI
(e.g., DCI format 2_6) may be referred to as a WUS PDCCH.
[0164] In the present disclosure, a method for defining WUS
monitoring and a method for determining a WUS monitoring occasion
according to DRX parameters are proposed. In the disclosure below,
on-duration (of DRX) associated with WUS may be a 1:1 mapping
between WUS and DRX cycle, a case of waking up in multiple DRX
cycles by one WUS may also be included. Performing PDCCH monitoring
in on-duration may mean performing monitoring of a configured
search space set during on-duration like the existing DRX
operation.
[0165] A method of configuring/controlling wake up for multiple DRX
cycles by one WUS may be as follows. The options below can be
implemented alone or in combination.
[0166] Option 1) If there are multiple DRX cycles between
consecutive WUS monitoring occasions without an indication of the
number of DRX cycles associated with one WUS, the UE may assume
that a WUS monitoring result before the multiple DRX cycles
determines whether to wake up in the multiple DRX cycles.
Alternatively, in the above case, the network may configure whether
to wake up all of the multiple DRX cycles or wake up only in the
first or some of the multiple DRX cycles. This may be effective for
a UE that occasionally receives a large amount of data.
[0167] Option 2) it configures a WUS monitoring occasion for each
DRX cycle, and it may indicate the number of DRX cycles (e.g., a
natural number of 0, 1 or 2 or more) to wake up (or to sleep)
through WUS transmitted on each WUS monitoring occasion. In this
case, even if the UE fails to detect a WUS, since it can detect a
WUS in the next DRX cycle, damage such as an increase in latency
can be reduced even when a WUS for multiple DRX cycles is not
detected. A UE instructed to wake up for multiple DRX cycles may
perform PDCCH monitoring without WUS detection on a WUS monitoring
occasion associated with the corresponding DRX cycle.
[0168] Hereinafter, the WUS operation based on the wake-up
operation will be mainly described, but the present disclosure may
be equally applied to a go-to-sleep (GTS) operation. For example,
the UE that has detected the WUS PDCCH performs the existing
operation (attempt to detect the PDCCH) in the DRX interval(s)
associated with or indicated for the WUS PDCCH, but, in some cases,
the UE detecting the WUS PDCCH may not perform all or part of the
existing operation in the associated or indicated DRX interval(s).
For example, when it is configured that WUS is necessarily
transmitted on all WUS occasions, or when one WUS DCI includes WUS
for multiple UEs, it may be assumed that a go-to-sleep rather than
a wake-up is applied.
[0169] <Determination of Monitoring Occasion for WUS>
[0170] For a monitoring occasion (or monitoring window) for WUS
DCI, a method of designating through an offset from the start point
of the associated DRX on-duration (option 1 to be described later)
and a method using an existing search space set configuration
(option 2 to be described later) may be considered.
[0171] Wake-up in DRX operation serves to configure whether to
monitor PDCCH in a specific DRX cycle(s), and more specifically,
configures whether to monitor PDCCH in on-duration of a specific
DRX cycle(s). The operation after the wake up may be performed in
the same way as the existing DRX operation. Therefore, it may be
assumed that the monitoring occasion configured by the proposal
below is valid only till the start point of the on-duration of the
next DRX cycle from the time when all transmissions/receptions in
the previous DRX cycle are finished. Alternatively, it may be
assumed that the monitoring occasion configured by the proposal
below is only in the DRX off-period, that is, in the non-active
time.
[0172] Meanwhile, in a specific situation in which WUS monitoring
is not possible, PDCCH monitoring may be performed in on-duration
associated with the corresponding WUS regardless of the WUS. As an
example, when one WUS indicates whether to wake up in multiple DRX
cycles, PDCCH monitoring may be performed only on-duration of the
first DRX cycle among the multiple DRX cycles, or PDCCH monitoring
may be performed on-duration of all associated DRX cycles.
[0173] In addition, if the UE fails to monitor the WUS in a
situation where one WUS is configured to indicate wake-up in
multiple DRX cycles, the network may instruct the UE i) whether to
perform PDCCH monitoring only on-duration of the first DRX cycle,
or ii) whether to perform PDCCH monitoring in on-duration of all
associated DRX cycles.
[0174] Option 1) Configure monitoring occasion for WUS DCI based on
offset from associated on-duration.
[0175] In the case of a method using an offset, such as option 1,
even when the DRX cycle is dynamically changed by multiple DRX
parameters, etc., there is an advantage that configure for the WUS
monitoring occasion can be applied without changing the parameters.
In addition, the following parameters for WUS monitoring may be
specified together with an offset from the start point of
on-duration (in this disclosure, the offset may mean an offset in a
previous direction with respect to the on-duration time).
[0176] All or part of the parameters below may be indicated to each
UE, and when some are indicated, all or part of the parameters not
indicated may be configured by a predefined definition. For
example, if the CORESET ID is not indicated, the CORESET for
monitoring the WUS DCI may be all or a part (e.g., a CORESET having
the lowest ID) of the CORESET configured at an active time. In
addition, the following contents may be configured for each offset
(when a plurality of offsets are applied), or the same
configuration may be applied to a plurality of offsets.
[0177] 1. CORESET ID
[0178] A. The CORESET ID that should be assumed in the resource
designated by the corresponding offset may be indicated
together.
[0179] B. When supporting multiple monitoring occasions, the
following method may be considered according to the characteristics
of the multiple monitoring occasions.
[0180] i. Multiple monitoring occasions for beam sweeping may be
considered in order to respond to a change in beam characteristics
due to a change in the location of the UE in the DRX off period. In
this case, multiple CORESET IDs and an offset corresponding to each
ID may be indicated. Alternatively, one offset and multiple CORESET
IDs may be indicated, and an offset between CORESETs may be
additionally indicated.
[0181] ii. In the case of multiple monitoring occasions to increase
the monitoring opportunity, when the WUS DCI cannot be transmitted
in the resource designated as the monitoring occasion (e.g., when
the corresponding slot is used as an uplink slot), it may be to
designate an additional monitoring occasion. In this case, a
plurality of offsets may be indicated, or X consecutive slots may
be configured as a monitoring occasion from a resource indicated by
a single offset and designated by the corresponding offset (or
offset by a predefined or network-directed interval (monitoring
occasion(s))).
[0182] 2. Symbol Offset within a Slot
[0183] A. The network may indicate not only the slot offset from
the on-duration start point, but also the symbol offset within the
corresponding slot.
[0184] B. The slot offset and the symbol offset may be indicated as
one parameter through joint encoding.
[0185] 3. A Monitored Aggregation Level (AL) and the Number of
Candidates for Each Aggregation Level
[0186] A. The network may indicate an AL that should be assumed in
WUS monitoring and the number of candidates for each AL.
[0187] B. The number of monitored ALs and candidates may be fixed
by predefined in order to reduce signaling overhead and the
like.
[0188] C. The symbol offset may be interpreted as indicating the
position of the first symbol of the associated CORESET in the
slot.
[0189] 4. Search Space (SS) Type
[0190] A. Since the method of determining the monitoring occasion
by the offset does not use the existing search space set
configuration, the types of search spaces belonging to the
corresponding monitoring occasion are not defined. Since this may
affect the determination of a demodulation reference signal (DMRS)
and a PDCCH scrambling parameter, it may be preferable to
additionally indicate the SS type in determining the monitoring
occasion of the offset indication method.
[0191] B. For example, when transmitting one WUS DCI to multiple
UEs, since it is preferable that the UEs assume the same
scrambling, it is preferable that scrambling by cell ID is applied
by designating search spaces in the corresponding monitoring
occasion as a common search space (CSS). On the other hand, when
the WUS DCI is transmitted to a specific UE only, it is preferable
that the corresponding scrambling is applied to UE-specific
parameters such as C-RNTI.
[0192] C. The search space type may be interpreted as a method of
instructing the UE whether the corresponding WUS DCI is a
group-based DCI or a UE-specific DCI. For example, when a
monitoring occasion for monitoring WUS DCI is configured with CSS,
the UE may perform decoding on the assumption of group-based
DCI.
[0193] The offset-type monitoring occasion designation method may
be implemented by applying different interpretations to some fields
of the existing search space set configuration. For example, among
parameters in the existing search space set configuration,
"monitoringSlotPeriodicityAndOffset" is used to indicate monitoring
periodicity and slot offset for the corresponding search space set.
In the search space set for WUS monitoring, the corresponding
parameter can be interpreted as an offset of the WUS monitoring
occasion with respect to the on-duration start point. The
parameters in the search space set configuration other than
"monitoringSlotPeriodicityAndOffset" can be applied in the existing
way or the above suggestions.
[0194] The slot offset proposed in the present disclosure may be
applied in the following manner.
[0195] Alt 1) Number of Slots
[0196] The offset may be interpreted as the number of slots
regardless of the slot type (e.g., downlink, uplink,
downlink+uplink). Accordingly, Alt 1 may be interpreted as a simple
time. For example, since 1 slot corresponds to 1 msec in numerology
of 15 kHz, the offset "X" configured by the present disclosure may
be interpreted (in 15 kHz neurology) as X slots, X msec.
[0197] Alt 2) Number of Downlink Slots
[0198] An offset may be applied based on slots configured in
downlink for all symbols, and/or slots configured in downlink for a
monitoring occasion configured for a UE. For example, when slot "N"
is the slot where DRX on-duration starts, when slot "N-1" is
configured as an uplink slot and slot "N-2" is configured as a
downlink slot, and when the slot offset of the WUS monitoring
occasion is 1, since the UE applies the offset based on only the
downlink slot, WUS monitoring can be performed in slot "N-2". This
can be effective as a method of preventing a case in which WUS
cannot be transmitted because the WUS monitoring occasion is
configured in the resource allocated to the uplink.
[0199] Alt 3) the number of available slots
[0200] Alt 3 may be a method including a flexible slot (or symbol)
in alt 2. That is, when a resource configured as a monitoring
occasion by WUS configuration is downlink or flexible, the UE may
apply the offset based on only the corresponding slots. Here, the
flexible may mean a resource in which uplink/downlink or not can be
determined by DCI format 2-0 or the like.
[0201] Option 2) Configure monitoring occasion for WUS DCI using
search space set configuration.
[0202] The following table is an example of a search space set
configuration.
TABLE-US-00007 TABLE 6 -- ASN1START -- TAG-SEARCHSPACE-START
SearchSpace ::= SEQUENCE { searchSpaceId SearchSpaceId,
controlResourceSetId ControlResourceSetId OPTIONAL, -- Cond
SetupOnly monitoringSlotPeriodicityAndOffset CHOICE { s11 NULL, s12
INTEGER (0..1), s14 INTEGER (0..3), s15 INTEGER (0..4), s18 INTEGER
(0..7), s110 INTEGER (0..9), s116 INTEGER (0..15), s120 INTEGER
(0..19), s140 INTEGER (0..39), s180 INTEGER (0..79), s1160 INTEGER
(0..159), s1320 INTEGER (0..319), s1640 INTEGER (0..639), s11280
INTEGER (0..1279), s12560 INTEGER (0..2559) } OPTIONAL, -- Cond
Setup duration INTEGER (2..2559) OPTIONAL, -- Need R
monitoringSymbolsWithinSlot BIT STRING (SIZE(14)) OPTIONAL, -- Cond
Setup nrofCandidates SEQUENCE { aggregationLevel1 ENUMERATED {n0,
n1, n2, n3, n4, n5, n6, n8}, aggregationLevel2 ENUMERATED {n0, n1,
n2, n3, n4, n5, n6, n8}, aggregationLevel4 ENUMERATED {n0, n1, n2,
n3, n4, n5, n6, n8}, aggregationLevel8 ENUMERATED {n0, n1, n2, n3,
n4, n5, n6, n8}, aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4,
n5, n6, n8} } OPTIONAL, -- Cond Setup searchSpaceType CHOICE {
common SEQUENCE { dci-Format0-0-AndFormat1-0 SEQUENCE { ... }
OPTIONAL, -- Need R dci-Format2-0 SEQUENCE { nrofCandidates-SFI
SEQUENCE { aggregationLevel1 ENUMERATED {n1, n2} OPTIONAL, -- Need
R aggregationLevel2 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel4 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel8 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel16 ENUMERATED {n1, n2} OPTIONAL -- Need R }, ... }
OPTIONAL, -- Need R dci-Format2-1 SEQUENCE { ... } OPTIONAL, --
Need R dci-Format2-2 SEQUENCE { ... } OPTIONAL, -- Need R
dci-Format2-3 SEQUENCE { dummy1 ENUMERATED {s11, s12, s14, s15,
s18, s110, s116, s120} OPTIONAL, -- Cond Setup dummy2 ENUMERATED
{n1, n2}, ... } OPTIONAL -- Need R }, ue-Specific SEQUENCE {
dci-Formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1},
... } } OPTIONAL -- Cond Setup } -- TAG-SEARCHSPACE-STOP --
ASN1STOP
[0203] In the table, `duration` is the number of consecutive slots
in the search space that lasts on every occasion given by
periodicity and offset (Number of consecutive slots that a
SearchSpace lasts in every occasion, i.e., upon every period as
given in the periodicityAndOffset).
[0204] `monitoringSlotPeriodicityAndOffset` indicates slots for
PDCCH monitoring composed of periodicity and offset. When the UE is
configured to monitor DCI format 2_1, only the values `sl1`, `sl2`
or `sl4` may be applicable. When the UE is configured to monitor
DCI format 2_0, only the values `sl1`, `sl2`, `sl4`, `sl5`, `sl8`,
`sl10`, `sl16` and `sl20` may be applicable.
[0205] `monitoringSymbolsWithinSlot` indicates the first symbol
(see SlotPeriodicityAndOffset and duration monitoring) for PDCCH
monitoring in a slot configured for PDCCH monitoring. The most
significant bit (left) bit represents the first OFDM symbol in the
slot, and the next most significant bit (left) bit represents the
second OFDM symbol in the slot. The bit(s) configured to 1
identifies the first OFDM symbol(s) of the CORESET within the slot.
When the cyclic prefix of the BWP is configured as an extended CP,
the last two bits in the bit stream are ignored by the UE. In the
case of DCI format 2_0, if the CORESET section identified by
`controlResourceSetId` represents three symbols, the first one
symbol is applied, and if the CORESET section identified by
controlResourceSetId represents two symbols, the first two symbols
are applied. When the CORESET section identified by
controlResourceSetId represents 1 symbol, the first three symbols
are applied.
[0206] `nrofCandidates-SFI` indicates the number of PDCCH
candidates for DCI format 2-0 for the configured aggregation level.
If there is no aggregation level, the UE does not search for
candidates having the corresponding aggregation level. A network
can configure only one aggregation level and a corresponding number
of candidates.
[0207] `nrofCandidates` indicates the number of PDCCH candidates
per aggregation level. The number of configured candidates and
aggregation levels can be applied to any format unless a specific
value is specified or a value for each format is provided.
[0208] When the monitoring occasion for WUS DCI is determined using
the existing search space set configuration, some of the monitoring
occasions configured in the search space set configuration can be
interpreted as WUS DCI, this may mean that WUS DCI is monitored for
one or more monitoring occasions closest to on-duration among the
monitoring occasions before on-duration. Parameters other than the
parameters for determining the monitoring occasion may be applied
in the conventional manner. The network may indicate how many
monitoring occasions WUS DCI is monitored before on-duration
together with the search space set configuration indicated to
monitor the WUS DCI.
[0209] Alternatively, the UE may monitor the WUS DCI only on an
available occasion among the monitoring occasions configured by the
search space set configuration, and the available occasion may be
defined by the following criteria.
[0210] The nearest valid occasion before X slots (or X msec) from
the start of the associated on-duration.
[0211] Here, a valid occasion is a duration in which the OFDM
symbol including the WUS PDCCH candidate is completely indicated as
downlink (DL) (characteristically, it may be a duration indicated
as DL by a semi-static configuration (configuration indicated by
RRC signaling) and/or a duration indicated as DL by dynamic SFI
(configuration indicated by DCI)) and a non-overlapping duration in
the time domain with the previous active time.
[0212] WUS PDCCH is not expected if a valid occasion has a gap of Y
slot (or Y msec) or more from the start point of on-duration, it
can be configured to perform PDCCH monitoring in the associated
on-duration(s) (X and Y can be configured to the same value).
[0213] The X and Y values may be configured or interpreted as
different values depending on the numerology of the (active) BWP
including the WUS SS (or monitoring the WUS).
[0214] The X and Y values may be configured or interpreted
differently depending on the DRX type (long/short) and/or the DRX
cycle value.
[0215] The X and Y values may include 0. 0 may mean that WUS
transmission is not expected. In this case, PDCCH monitoring is
performed in the associated on-duration.
[0216] The network may indicate a plurality of search space set
configurations for WUS DCI monitoring. This may be interpreted as a
method for transmitting and receiving WUS DCI using a CORESET
linked to different TCIs, or as a method for configuring a
monitoring occasion adaptively to various DRX configurations.
[0217] FIG. 15 illustrates a WUS monitoring occasion.
[0218] Referring to FIG. 15, the WUS monitoring occasion may be
determined based on a message configuring a search space as shown
in Table 6. Here, the WUS may be a DCI format including a wake-up
indication. For example, DCI format 2_6 is a DCI format used to
inform the UE of power saving information outside the DRX active
time, DCI format 2_6 may include, for example, a wake-up indication
(1 bit), information related to dormancy of the secondary cell, and
the like. This DCI format is transmitted through the PDCCH.
Accordingly, the WUS monitoring may be expressed as one of PDCCH
monitoring.
[0219] As described above, `monitoringSlotPeriodicityAndOffset` of
Table 6 may inform slots for PDCCH monitoring based on periodicity
and offset, it can be said that these slots correspond to the
occasion for PDCCH monitoring. In addition, `duration` indicates
consecutive slots in which the search space is continued in each
occasion. In FIGS. 15, 151 and 152 may be referred to as PDCCH
monitoring occasions configured by
`monitoringSlotPeriodicityAndOffset`, the search space continues in
three consecutive slots on each PDCCH monitoring occasion.
[0220] Meanwhile, among the PDCCH monitoring occasions configured
as above, the PDCCH monitoring occasion capable of monitoring the
WUS may be limited to being within the interval (Let's call this
the WUS monitoring window) between the start slot of the DRX On
duration (i.e. slot where drx-onDurationTimer starts, 153) and the
time 154 indicated by the offset (ps-offset) value. That is, in
FIG. 15, 151 is outside the WUS monitoring window, and 152 is
within the WUS monitoring window. Therefore, the UE may perform
PDCCH monitoring for WUS detection only on the PDCCH monitoring
occasion corresponding to 152.
[0221] When the UE detects the WUS within the WUS monitoring
window, the UE may perform a necessary operation in the DRX on
duration based on the WUS. For example, if the WUS instructs the UE
to wake up, PDCCH monitoring for detecting a general DCI format
other than the WUS may be performed by waking up in the DRX on
duration.
[0222] Above, it was proposed to monitor WUS DCI only on available
occasions among monitoring occasions configured by the search space
set configuration. This may mean that when the monitoring
periodicity of the search space set and the DRX cycle do not have a
multiple relationship, the distance between the on-duration and the
WUS monitoring occasion may appear differently for each DRX cycle.
In this case, since it cannot be assumed that the time for the UE
to prepare for PDCCH monitoring in on-duration is constant, the
complexity of the UE implementation may increase. In order to solve
such a problem, the present disclosure proposes to align the
monitoring periodicity of the search space set and the DRX cycle,
and the following method may be considered.
[0223] Method 1) It can be assumed that only a value common to the
DRX cycle is used for the monitoring periodicity of the WUS search
space set. For example, if a long DRX cycle can be configured with
a value of one of {10 ms, 20 ms, 32 ms, 40 ms, 60 ms, 64 ms, 70 ms,
80 ms, 128 ms, 160 ms, 256 ms, 320 ms, 512 ms, 640 ms, 1024 ms,
1280 ms, 2048 ms, 2560 ms, 5120 ms, 10240 ms}, the monitoring
periodicity of the search space set can be configured as a value of
one of {1 slot, 2 slots, 4 slots, 5 slots, 8 slots, 10 slots, 16
slots, 20 slots, 40 slots, 80 slots, 160 slots, 320 slots, 640
slots, 1280 slots, 2560 slots}. Method 1 may mean that it is
assumed that the WUS monitoring periodicity is indicated only by a
common value in the two configurations.
[0224] Method 2) It can be assumed that the monitoring periodicity
of the WUS search space set is selected from the DRX cycle pool or
that the monitoring periodicity of the WUS search space set is the
same as the associated DRX cycle. If monitoring periodicity and DRX
cycle are defined differently in the number and value that can be
selected, by defining a 1:1 mapping relationship between monitoring
periodicity and DRX cycle in the search space set configuration, it
can be defined that each monitoring periodicity selectable in the
search space set configuration means each DRX cycle in the DRX
configuration. Or, in a simple way, it is assumed that the
monitoring periodicity of the WUS search space set is the same as
the associated DRX cycle, and it may be defined that only the
offset from the on-duration start point is indicated in
"lotPeriodicityAndOffset" of the search space set configuration. In
this way, it is possible to designate the monitoring periodicity
for the WUS DCI at a certain distance from the on-duration of the
DRX cycle.
[0225] <Skip WUS Monitoring>
[0226] If the WUS monitoring occasion is more than a certain
distance away from the DRX on-duration, an inefficient operation
such as performing unnecessary wake-up for WUS monitoring and
performing a sleep operation again for a predetermined time until
on-duration when a WUS is detected may occur.
[0227] In the present disclosure, in order to alleviate this
inefficiency, when the WUS monitoring occasion is apart from the
associated DRX on-duration for a predetermined time(a certain time)
or more, it is proposed to skip (omit) WUS monitoring. Here, since
skipping PDCCH monitoring in on-duration associated with the
skipped monitoring occasion may increase delay (latency), wake-up
and PDCCH monitoring may be performed in on-duration associated
with the skipped monitoring occasion. In this case, the time
interval for determining whether to skip may be predefined or may
be indicated by the network (e.g., through higher layer signaling,
etc.).
[0228] The UE may follow the existing DRX operation if the WUS
monitoring occasion is not valid or if there is no WUS monitoring
occasion other than the active time.
[0229] FIGS. 16 and 17 illustrate a case in which an occasion for
WUS monitoring is located in the WUS monitoring window and a case
in which it is not.
[0230] Referring to FIG. 16, for example, a plurality of PDCCH
monitoring occasions (i.e., PDCCH monitoring occasions #1 and 2)
for WUS detection may be configured for the UE. When a WUS is
detected in these PDCCH monitoring occasions, an operation based on
the WUS may be performed in the next DRX cycle 161. In this sense,
the PDCCH monitoring occasions can be said to be related to
(associated with) the next DRX cycle 161.
[0231] Meanwhile, among the plurality of PDCCH monitoring
occasions, PDCCH monitoring occasion #2 is located within the WUS
monitoring window, and PDCCH monitoring occasion #1 is located
outside the WUS monitoring window. Therefore, the UE performs PDCCH
monitoring for WUS detection only on PDCCH monitoring occasion
#2.
[0232] On the other hand, in FIG. 17, a plurality of PDCCH
monitoring occasions (i.e., PDCCH monitoring occasions #1 and 2)
configured for the UE for WUS detection are all located outside the
WUS monitoring window. In this case, it can be expressed that the
UE does not have a PDCCH monitoring occasion for WUS detection
outside (before) the next DRX on duration (or active time). In this
case, the UE does not perform WUS monitoring.
[0233] However, when the UE does not perform WUS monitoring because
it does not have a PDCCH monitoring occasion for WUS detection
outside (before) the next DRX on duration (or active time), a
problem arises as to which operation the UE should perform in the
next DRX ON duration.
[0234] In the present disclosure, when a search space set is
provided so that the UE monitors the PDCCH for detection of DCI
format 2_6 (WUS signal) in the active DL BWP of PCell or SpCell,
and the UE does not have any PDCCH monitoring occasion for
detection of DCI format 2_6 outside the active time of the next DRX
cycle, it is proposed that the UE wakes up, starts
`drx-onDurationTimer` in the next DRX cycle, and performs PDCCH
monitoring.
[0235] FIG. 18 illustrates a PDCCH monitoring operation method of a
UE according to an embodiment of the present disclosure.
[0236] Referring to FIG. 18, the UE receives a configuration
message indicating at least one monitoring occasion for WUS
detection (e.g., a message configuring a search space) (S181). The
WUS may be downlink control information (DCI) including a wake-up
indication.
[0237] The UE determines whether the at least one monitoring
occasion exists within the WUS monitoring window (e.g., the time
window between the time determined by the offset and the start time
of the next DRX on duration) (S182), if the at least one monitoring
occasion does not exist within the WUS monitoring window, the WUS
monitoring is skipped, PDCCH monitoring is performed by waking up
(starting drx-onDurationTimer) in the next DRX cycle (S183). For
example, if the at least one monitoring occasion is located a
predetermined time before the start time of the next DRX on
duration, PDCCH monitoring is performed in the next DRX On
duration.
[0238] If the at least one monitoring occasion is located within
the predetermined time from the start time of the next DRX-on
duration, monitoring for the WUS detection is performed. On the
other hand, if the at least one monitoring occasion is located
before the predetermined time from the start time of the next
DRX-on duration, monitoring for the WUS detection is not performed
and PDCCH monitoring is performed by waking up at the start time of
the next DRX-on duration.
[0239] The network (base station) may provide a message indicating
the predetermined time to the UE.
[0240] FIG. 19 shows a specific example to which FIG. 18 is
applied.
[0241] Referring to FIG. 19, the UE provided with search space sets
for monitoring the PDCCH for WUS (specific DCI format, for example,
DCI format 2_6) detection determines whether it has a PDCCH
monitoring occasion for detecting the WUS outside (i.e., before)
the active time of the next DRX cycle (S191).
[0242] If the UE does not have a PDCCH monitoring occasion for the
WUS detection, the UE starts drx-onDurationTimer for the next DRX
cycle (i.e., wakes up in the next DRX cycle to perform general
PDCCH monitoring) (S192).
[0243] From the side of the base station, the processor of the base
station transmits a configuration message informing of at least one
monitoring occasion for detecting a wake up signal (WUS), if the at
least one monitoring occasion is located before a predetermined
time from the start time of the next discontinuous reception
(DRX)-on duration, the PDCCH may be transmitted in the next DRX-on
duration.
[0244] Meanwhile, some exceptional examples in which PDCCH cannot
be monitored (e.g., collision with SSB, rate matching resources
(e.g., LTE CRS) and resources configured as uplink by DCI format
2_0) may be defined. If the resource configured for PS-PDCCH
monitoring outside of the active time overlaps with the
above-mentioned exceptional example, the UE cannot monitor the
PS-PDCCH. In this case, a fallback operation must be defined, and
the possible fallback operations can be as follows. That is,
PS-PDCCH monitoring is skipped, but PDCCH monitoring may be
performed in the corresponding DRX on-duration. If the resource for
PS-PDCCH monitoring is not available, the UE monitors the
configured PDCCH at the active time.
[0245] FIG. 20 shows an example of applying the method described in
FIGS. 18 and 19 between a network and a UE.
[0246] Referring to FIG. 20, a network (e.g., a base station)
provides a message including an offset (ps-offset) related to WUS
monitoring to the UE (S201). For example, the base station may
inform the WUS monitoring-related offset (ps-offset) through a
`physical cell group configuration` message used to configure
cell-group specific physical layer (L1) parameters. The offset may
indicate a start time of the search of DCI format 2_6 with CRC
scrambled by PS-RNTI.
[0247] The network provides a configuration message (e.g., a search
space configuration message) informing the UE of the WUS monitoring
occasion (S202).
[0248] The UE determines whether there is the WUS (PDCCH)
monitoring occasion within the time window (the aforementioned WUS
monitoring window) based on the offset (ps-offset) and the start
slot of the next DRX-on duration (S203), if there is no WUS
monitoring occasion within the time window, the UE skips WUS
monitoring and wakes up at the next DRX-on duration to perform
PDCCH monitoring (S204).
[0249] When the WUS monitoring occasion is more than a certain
distance away from the DRX on duration, WUS monitoring may be
unnecessary depending on the rate of change in the channel
environment or the type of service. To perform WUS monitoring in
the above case, it is necessary to perform an unnecessary wake up,
when the WUS is detected, it may be inefficient, such as it may be
necessary to perform a sleep operation again for a predetermined
time until the DRX on duration. In the present disclosure, in order
to alleviate this inefficiency, when the WUS monitoring occasion is
spaced apart from the associated DRX on-duration for a
predetermined time or more, it is proposed to skip WUS monitoring
and to perform PDCCH monitoring (for general DCI format) in DRX
on-duration associated with the skipped WUS monitoring occasion.
This is because if the PDCCH monitoring is skipped, latency may
increase.
[0250] <Determination of Monitoring Occasion for WUS Considering
DRX Cycle/Type>
[0251] In NR, the DRX operation may comprise short DRX, long DRX,
etc. (When both short/long DRX are configured) Short DRX performs
DRX operation with a relatively short cycle compared to long DRX.
If the PDCCH is not continuously detected in the short DRX, an
operation in which the long DRX is applied is performed.
[0252] When this DRX operation is linked with the WUS operation,
for all DRX types and/or for a short DRX cycle, monitoring for WUS
DCI may act as overhead due to WUS transmission and reception and
overhead in terms of WUS detection/decoding of the UE, the power
savings gain can also be severely reduced. In addition, when both
short/long DRX having different DRX cycles are configured and the
WUS monitoring occasion is determined by the existing search space
set configuration, depending on the DRX type, a problem may occur
that the location of the monitoring occasion is not constant. In
order to solve this problem, the present disclosure proposes to
apply different WUS monitoring configurations according to the DRX
type and/or cycle, the following method can be considered. The
methods below may be implemented alone or in combination. In
addition, the WUS monitoring configuration below may include the
offset method and the search space set configuration suggested
above.
[0253] Method 1) DRX Type Specific WUS Monitoring Configuration
[0254] The network may indicate different WUS monitoring
configuration according to the DRX type. For example, a WUS
monitoring configuration for a long DRX operation and a WUS
monitoring configuration for a short DRX operation may be
separately indicated (In this case, the WUS monitoring
configuration may include not only the location of the WUS
monitoring occasion but also configurations related to WUS
monitoring, such as the number of WUS monitoring occasions). The UE
may select and apply the WUS monitoring configuration based on the
currently applied DRX type. For example, the network does not
indicate WUS monitoring configuration for short DRX and does
indicate WUS monitoring configuration only for long DRX. In this
case, the UE always performs PDCCH monitoring in the on-duration
within the short DRX interval and, in the long DRX interval, WUS
detection is performed according to the indicated WUS monitoring
configuration. And when a WUS is detected, PDCCH monitoring may be
performed in the associated on-duration.
[0255] When applying the monitoring occasion determination method
proposed above to method 1, the network may indicate an offset for
defining a WUS monitoring occasion for each DRX type or indicate a
search space set configuration. In this case, the WUS monitoring
configuration may include always monitoring the PDCCH without WUS
monitoring or performing a sleep operation in a specific DRX cycle
without WUS monitoring.
[0256] In order to additionally reduce signaling overhead and
reduce the complexity of UE operation, in the short DRX operation,
a method of performing PDCCH monitoring without performing WUS
monitoring regardless of whether WUS is configured (or without
configuring WUS) may be considered.
[0257] Method 2) DRX Cycle Specific WUS Monitoring
[0258] When the DRX cycle is short (for example, a DRX cycle of
less than 10 ms), since a relatively short period is configured for
on-duration within the corresponding DRX cycle, performing WUS
monitoring every DRX cycle may be negative in that the power saving
effect is low and the complexity of the UE due to WUS monitoring
may increase. Therefore, the present disclosure suggests that the
WUS monitoring operation performed according to the DRX cycle be
configured differently.
[0259] In the simplest way, when a DRX cycle smaller than that
value is configured by specifying a specific value (e.g., 10 ms)
among DRX cycles, a method of performing PDCCH monitoring in
on-duration without WUS monitoring may be considered. In this case,
the specific value may be predefined or indicated by a network.
[0260] As another method, different WUS monitoring configurations
may be indicated for each DRX cycle duration. In this case, the WUS
monitoring configuration may include not only the location of the
WUS monitoring occasion but also configurations related to WUS
monitoring, such as the number of WUS monitoring occasions. For
example, by specifying a specific value (e.g., 10 ms) among the DRX
cycles, a WUS monitoring configuration for a DRX cycle smaller than
the corresponding value and a WUS monitoring configuration (e.g.
the use of offsets and/or search space set configuration) for a DRX
cycle larger than the corresponding value may be indicated,
respectively. And the UE may apply the indicated WUS monitoring
configuration according to the configured DRX cycle.
[0261] Additionally, in order to reduce signaling overhead and
reduce the complexity of UE operation, in the DRX operation in
which a DRX cycle smaller than a specific value is configured, a
method of performing PDCCH monitoring without performing WUS
monitoring regardless of whether WUS is configured (or without
configuring WUS) may be considered.
[0262] FIG. 21 illustrates a wireless device applicable to the
present specification.
[0263] Referring to FIG. 21, a first wireless device 100 and a
second wireless device 200 may transmit radio signals through a
variety of RATs (e.g., LTE and NR).
[0264] The first wireless device 100 may include one or more
processors 102 and one or more memories 104 and additionally
further include one or more transceivers 106 and/or one or more
antennas 108. The processors 102 may control the memory 104 and/or
the transceivers 106 and may be configured to implement the
descriptions, functions, procedures, proposals, methods, and/or
operational flowcharts disclosed in this document. For example, the
processors 102 may process information within the memory 104 to
generate first information/signals and then transmit radio signals
including the first information/signals through the transceivers
106. In addition, the processor 102 may receive radio signals
including second information/signals through the transceiver 106
and then store information obtained by processing the second
information/signals in the memory 104. The memory 104 may be
connected to the processor 102 and may store a variety of
information related to operations of the processor 102. For
example, the memory 104 may store software code including commands
for performing a part or the entirety of processes controlled by
the processor 102 or for performing the descriptions, functions,
procedures, proposals, methods, and/or operational flowcharts
disclosed in this document. Herein, the processor 102 and the
memory 104 may be a part of a communication modem/circuit/chip
designed to implement RAT (e.g., LTE or NR). The transceiver 106
may be connected to the processor 102 and transmit and/or receive
radio signals through one or more antennas 108. The transceiver 106
may include a transmitter and/or a receiver. The transceiver 106
may be interchangeably used with a radio frequency (RF) unit. In
the present specification, the wireless device may represent a
communication modem/circuit/chip.
[0265] The second wireless device 200 may include one or more
processors 202 and one or more memories 204 and additionally
further include one or more transceivers 206 and/or one or more
antennas 208. The processor 202 may control the memory 204 and/or
the transceiver 206 and may be configured to implement the
descriptions, functions, procedures, proposals, methods, and/or
operational flowcharts disclosed in this document. For example, the
processor 202 may process information within the memory 204 to
generate third information/signals and then transmit radio signals
including the third information/signals through the transceiver
206. In addition, the processor 202 may receive radio signals
including fourth information/signals through the transceiver 106
and then store information obtained by processing the fourth
information/signals in the memory 204. The memory 204 may be
connected to the processor 202 and may store a variety of
information related to operations of the processor 202. For
example, the memory 204 may store software code including commands
for performing a part or the entirety of processes controlled by
the processor 202 or for performing the descriptions, functions,
procedures, proposals, methods, and/or operational flowcharts
disclosed in this document. Herein, the processor 202 and the
memory 204 may be a part of a communication modem/circuit/chip
designed to implement RAT (e.g., LTE or NR). The transceiver 206
may be connected to the processor 202 and transmit and/or receive
radio signals through one or more antennas 208. The transceiver 206
may include a transmitter and/or a receiver. The transceiver 206
may be interchangeably used with an RF unit. In the present
specification, the wireless device may represent a communication
modem/circuit/chip.
[0266] Hereinafter, hardware elements of the wireless devices 100
and 200 will be described more specifically. One or more protocol
layers may be implemented by, without being limited to, one or more
processors 102 and 202. For example, the one or more processors 102
and 202 may implement one or more layers (e.g., functional layers
such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more
processors 102 and 202 may generate one or more Protocol Data Units
(PDUs) and/or one or more Service Data Unit (SDUs) according to the
descriptions, functions, procedures, proposals, methods, and/or
operational flowcharts disclosed in this document. The one or more
processors 102 and 202 may generate messages, control information,
data, or information according to the descriptions, functions,
procedures, proposals, methods, and/or operational flowcharts
disclosed in this document. The one or more processors 102 and 202
may generate signals (e.g., baseband signals) including PDUs, SDUs,
messages, control information, data, or information according to
the descriptions, functions, procedures, proposals, methods, and/or
operational flowcharts disclosed in this document and provide the
generated signals to the one or more transceivers 106 and 206. The
one or more processors 102 and 202 may receive the signals (e.g.,
baseband signals) from the one or more transceivers 106 and 206 and
acquire the PDUs, SDUs, messages, control information, data, or
information according to the descriptions, functions, procedures,
proposals, methods, and/or operational flowcharts disclosed in this
document.
[0267] The one or more processors 102 and 202 may be referred to as
controllers, microcontrollers, microprocessors, or microcomputers.
The one or more processors 102 and 202 may be implemented by
hardware, firmware, software, or a combination thereof. For
example, one or more Application Specific Integrated Circuits
(ASICs), one or more Digital Signal Processors (DSPs), one or more
Digital Signal Processing Devices (DSPDs), one or more Programmable
Logic Devices (PLDs), or one or more Field Programmable Gate Arrays
(FPGAs) may be included in the one or more processors 102 and 202.
The one or more processors 102 and 202 may be implemented with at
least one computer readable medium (CRM) including instructions to
be executed by at least one processor.
[0268] For example, each method described in FIGS. 18 to 20 may be
performed by at least one computer-readable recording medium (CRM)
including instructions based on being executed by at least one
processor. The CRM may perform, for example, receiving a
configuration message indicating at least one monitoring occasion
for detecting a wake-up signal (WUS), if the at least one
monitoring occasion is located a predetermined time before the
start time of the next discontinuous reception (DRX)-on duration,
performing PDCCH monitoring in the next DRX-on duration.
[0269] The descriptions, functions, procedures, proposals, methods,
and/or operational flowcharts disclosed in this document may be
implemented using firmware or software and the firmware or software
may be configured to include the modules, procedures, or functions.
Firmware or software configured to perform the descriptions,
functions, procedures, proposals, methods, and/or operational
flowcharts disclosed in this document may be included in the one or
more processors 102 and 202 or stored in the one or more memories
104 and 204 so as to be driven by the one or more processors 102
and 202. The descriptions, functions, procedures, proposals,
methods, and/or operational flowcharts disclosed in this document
may be implemented using firmware or software in the form of code,
commands, and/or a set of commands.
[0270] The one or more memories 104 and 204 may be connected to the
one or more processors 102 and 202 and store various types of data,
signals, messages, information, programs, code, instructions,
and/or commands. The one or more memories 104 and 204 may be
configured by Read-Only Memories (ROMs), Random Access Memories
(RAMs), Electrically Erasable Programmable Read-Only Memories
(EPROMs), flash memories, hard drives, registers, cash memories,
computer-readable storage media, and/or combinations thereof. The
one or more memories 104 and 204 may be located at the interior
and/or exterior of the one or more processors 102 and 202. In
addition, the one or more memories 104 and 204 may be connected to
the one or more processors 102 and 202 through various technologies
such as wired or wireless connection.
[0271] The one or more transceivers 106 and 206 may transmit user
data, control information, and/or radio signals/channels, mentioned
in the methods and/or operational flowcharts of this document, to
one or more other devices. The one or more transceivers 106 and 206
may receive user data, control information, and/or radio
signals/channels, mentioned in the descriptions, functions,
procedures, proposals, methods, and/or operational flowcharts
disclosed in this document, from one or more other devices. For
example, the one or more transceivers 106 and 206 may be connected
to the one or more processors 102 and 202 and transmit and receive
radio signals. For example, the one or more processors 102 and 202
may perform control so that the one or more transceivers 106 and
206 may transmit user data, control information, or radio signals
to one or more other devices. In addition, the one or more
processors 102 and 202 may perform control so that the one or more
transceivers 106 and 206 may receive user data, control
information, or radio signals from one or more other devices. In
addition, the one or more transceivers 106 and 206 may be connected
to the one or more antennas 108 and 208 and the one or more
transceivers 106 and 206 may be configured to transmit and receive
user data, control information, and/or radio signals/channels,
mentioned in the descriptions, functions, procedures, proposals,
methods, and/or operational flowcharts disclosed in this document,
through the one or more antennas 108 and 208. In this document, the
one or more antennas may be a plurality of physical antennas or a
plurality of logical antennas (e.g., antenna ports). The one or
more transceivers 106 and 206 may convert received radio
signals/channels etc. from RF band signals into baseband signals in
order to process received user data, control information, radio
signals/channels, etc. using the one or more processors 102 and
202. The one or more transceivers 106 and 206 may convert the user
data, control information, radio signals/channels, etc. processed
using the one or more processors 102 and 202 from the base band
signals into the RF band signals. To this end, the one or more
transceivers 106 and 206 may include (analog) oscillators and/or
filters.
[0272] FIG. 22 shows an example of a structure of a signal
processing module. Herein, signal processing may be performed in
the processors 102 and 202 of FIG. 21.
[0273] Referring to FIG. 22, the transmitting device (e.g., a
processor, the processor and a memory, or the processor and a
transceiver) in a UE or BS may include a scrambler 301, a modulator
302, a layer mapper 303, an antenna port mapper 304, a resource
block mapper 305, and a signal generator 306.
[0274] The transmitting device can transmit one or more codewords.
Coded bits in each codeword are scrambled by the corresponding
scrambler 301 and transmitted over a physical channel A codeword
may be referred to as a data string and may be equivalent to a
transport block which is a data block provided by the MAC
layer.
[0275] Scrambled bits are modulated into complex-valued modulation
symbols by the corresponding modulator 302. The modulator 302 can
modulate the scrambled bits according to a modulation scheme to
arrange complex-valued modulation symbols representing positions on
a signal constellation. The modulation scheme is not limited and
m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude
Modulation) may be used to modulate the coded data. The modulator
may be referred to as a modulation mapper.
[0276] The complex-valued modulation symbols can be mapped to one
or more transport layers by the layer mapper 303. Complex-valued
modulation symbols on each layer can be mapped by the antenna port
mapper 304 for transmission on an antenna port.
[0277] Each resource block mapper 305 can map complex-valued
modulation symbols with respect to each antenna port to appropriate
resource elements in a virtual resource block allocated for
transmission. The resource block mapper can map the virtual
resource block to a physical resource block according to an
appropriate mapping scheme. The resource block mapper 305 can
allocate complex-valued modulation symbols with respect to each
antenna port to appropriate subcarriers and multiplex the
complex-valued modulation symbols according to a user.
[0278] Signal generator 306 can modulate complex-valued modulation
symbols with respect to each antenna port, that is,
antenna-specific symbols, according to a specific modulation
scheme, for example, OFDM (Orthogonal Frequency Division
Multiplexing), to generate a complex-valued time domain OFDM symbol
signal. The signal generator can perform IFFT (Inverse Fast Fourier
Transform) on the antenna-specific symbols, and a CP (cyclic
Prefix) can be inserted into time domain symbols on which IFFT has
been performed. OFDM symbols are subjected to digital-analog
conversion and frequency up-conversion and then transmitted to the
receiving device through each transmission antenna. The signal
generator may include an IFFT module, a CP inserting unit, a
digital-to-analog converter (DAC) and a frequency upconverter.
[0279] FIG. 23 shows another example of a structure of a signal
processing module in a transmitting device. Herein, signal
processing may be performed in a processor of a UE/BS, such as the
processors 102 and 202 of FIG. 21.
[0280] Referring to FIG. 23, the transmitting device (e.g., a
processor, the processor and a memory, or the processor and a
transceiver) in the UE or the BS may include a scrambler 401, a
modulator 402, a layer mapper 403, a precoder 404, a resource block
mapper 405, and a signal generator 406.
[0281] The transmitting device can scramble coded bits in a
codeword by the corresponding scrambler 401 and then transmit the
scrambled coded bits through a physical channel.
[0282] Scrambled bits are modulated into complex-valued modulation
symbols by the corresponding modulator 402. The modulator can
modulate the scrambled bits according to a predetermined modulation
scheme to arrange complex-valued modulation symbols representing
positions on a signal constellation. The modulation scheme is not
limited and pi/2-BPSK (pi/2-Binary Phase Shift Keying), m-PSK
(m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation)
may be used to modulate the coded data.
[0283] The complex-valued modulation symbols can be mapped to one
or more transport layers by the layer mapper 403.
[0284] Complex-valued modulation symbols on each layer can be
precoded by the precoder 404 for transmission on an antenna port.
Here, the precoder may perform transform precoding on the
complex-valued modulation symbols and then perform precoding.
Alternatively, the precoder may perform precoding without
performing transform precoding. The precoder 404 can process the
complex-valued modulation symbols according to MIMO using multiple
transmission antennas to output antenna-specific symbols and
distribute the antenna-specific symbols to the corresponding
resource block mapper 405. An output z of the precoder 404 can be
obtained by multiplying an output y of the layer mapper 403 by an
N.times.M precoding matrix W. Here, N is the number of antenna
ports and M is the number of layers.
[0285] Each resource block mapper 405 maps complex-valued
modulation symbols with respect to each antenna port to appropriate
resource elements in a virtual resource block allocated for
transmission.
[0286] The resource block mapper 405 can allocate complex-valued
modulation symbols to appropriate subcarriers and multiplex the
complex-valued modulation symbols according to a user.
[0287] Signal generator 406 can modulate complex-valued modulation
symbols according to a specific modulation scheme, for example,
OFDM, to generate a complex-valued time domain OFDM symbol signal.
The signal generator 406 can perform IFFT (Inverse Fast Fourier
Transform) on antenna-specific symbols, and a CP (cyclic Prefix)
can be inserted into time domain symbols on which IFFT has been
performed. OFDM symbols are subjected to digital-analog conversion
and frequency up-conversion and then transmitted to the receiving
device through each transmission antenna. The signal generator 406
may include an IFFT module, a CP inserting unit, a
digital-to-analog converter (DAC) and a frequency upconverter.
[0288] The signal processing procedure of the receiving device may
be reverse to the signal processing procedure of the transmitting
device. Specifically, the processor of the transmitting device
decodes and demodulates RF signals received through antenna ports
of the transceiver. The receiving device may include a plurality of
reception antennas, and signals received through the reception
antennas are restored to baseband signals, and then multiplexed and
demodulated according to MIMO to be restored to a data string
intended to be transmitted by the transmitting device. The
receiving device may include a signal restoration unit that
restores received signals to baseband signals, a multiplexer for
combining and multiplexing received signals, and a channel
demodulator for demodulating multiplexed signal strings into
corresponding codewords. The signal restoration unit, the
multiplexer and the channel demodulator may be configured as an
integrated module or independent modules for executing functions
thereof. More specifically, the signal restoration unit may include
an analog-to-digital converter (ADC) for converting an analog
signal into a digital signal, a CP removal unit that removes a CP
from the digital signal, an FET module for applying FFT (fast
Fourier transform) to the signal from which the CP has been removed
to output frequency domain symbols, and a resource element
demapper/equalizer for restoring the frequency domain symbols to
antenna-specific symbols. The antenna-specific symbols are restored
to transport layers by the multiplexer and the transport layers are
restored by the channel demodulator to codewords intended to be
transmitted by the transmitting device.
[0289] FIG. 24 illustrates an example of a wireless communication
device according to an implementation example of the present
disclosure.
[0290] Referring to FIG. 24, the wireless communication device, for
example, a UE may include at least one of a processor 2310 such as
a digital signal processor (DSP) or a microprocessor, a transceiver
2335, a power management module 2305, an antenna 2340, a battery
2355, a display 2315, a keypad 2320, a global positioning system
(GPS) chip 2360, a sensor 2365, a memory 2330, a subscriber
identification module (SIM) card 2325, a speaker 2345 and a
microphone 2350. A plurality of antennas and a plurality of
processors may be provided.
[0291] The processor 2310 can implement functions, procedures and
methods described in the present description. The processor 2310 in
FIG. 24 may be the processors 102 and 202 in FIG. 21.
[0292] The memory 2330 is connected to the processor 2310 and
stores information related to operations of the processor. The
memory may be located inside or outside the processor and connected
to the processor through various techniques such as wired
connection and wireless connection. The memory 2330 in FIG. 24 may
be the memories 104 and 204 in FIG. 21.
[0293] A user can input various types of information such as
telephone numbers using various techniques such as pressing buttons
of the keypad 2320 or activating sound using the microphone 2350.
The processor 2310 can receive and process user information and
execute an appropriate function such as calling using an input
telephone number. In some scenarios, data can be retrieved from the
SIM card 2325 or the memory 2330 to execute appropriate functions.
In some scenarios, the processor 2310 can display various types of
information and data on the display 2315 for user convenience.
[0294] The transceiver 2335 is connected to the processor 2310 and
transmit and/or receive RF signals. The processor can control the
transceiver in order to start communication or to transmit RF
signals including various types of information or data such as
voice communication data. The transceiver includes a transmitter
and a receiver for transmitting and receiving RF signals. The
antenna 2340 can facilitate transmission and reception of RF
signals. In some implementation examples, when the transceiver
receives an RF signal, the transceiver can forward and convert the
signal into a baseband frequency for processing performed by the
processor. The signal can be processed through various techniques
such as converting into audible or readable information to be
output through the speaker 2345. The transceiver in FIG. 24 may be
the transceivers 106 and 206 in FIG. 21.
[0295] Although not shown in FIG. 24, various components such as a
camera and a universal serial bus (USB) port may be additionally
included in the UE. For example, the camera may be connected to the
processor 2310.
[0296] FIG. 24 is an example of implementation with respect to the
UE and implementation examples of the present disclosure are not
limited thereto. The UE need not essentially include all the
components shown in FIG. 24. That is, some of the components, for
example, the keypad 2320, the GPS chip 2360, the sensor 2365 and
the SIM card 2325 may not be essential components. In this case,
they may not be included in the UE.
[0297] FIG. 25 shows an example of a processor 2000.
[0298] Referring to FIG. 25, the processor 2000 may include a
control channel monitoring unit 2010 and a data channel receiving
unit 2020. The processor 2000 may execute the methods (the position
of the receiver) described with reference to FIGS. 18 to 20. For
example, the processor 2000 may receive an offset based on the
start slot of the discontinuous reception (DRX)-on duration and
monitor the WUS in a time window between the time based on the
offset and the start slot. If there is no WUS monitoring occasion
within the time window, the WUS monitoring is skipped, but the
PDCCH monitoring is performed by waking up at the next DRX-on
duration. Thereafter, a PDSCH may be received (or a PUSCH
transmitted) based on the PDCCH. The processor 2000 may be an
example of the processors 102 and 202 of FIG. 21.
[0299] FIG. 26 shows an example of a processor 3000.
[0300] Referring to FIG. 26, the processor 3000 may include a
control information/data generation module 3010 and a transmission
module 3020. The processor 3000 may execute the methods described
from the perspective of the transmitter in FIGS. 18 to 20. For
example, the processor 3000 may generate an offset based on the
start slot of the discontinuous reception (DRX)-on duration, and
then inform the UE. In addition, the WUS monitoring occasion can be
configured to the UE. WUS may be transmitted on at least one of WUS
monitoring occasions. The processor 3000 transmits a PDCCH
including scheduling information in Discontinuous reception
(DRX)-on duration and based on the PDCCH, a PDSCH may be
transmitted or a PUSCH may be received. The processor 3000 may be
an example of the processors 102 and 202 of FIG. 21.
[0301] FIG. 27 shows another example of a wireless device.
[0302] FIG. 27, a wireless device may include at least one
processor 102 and 202, at least one memory 104 and 204, at least
one transceiver 106 and 206, and one or more antennas 108 and
208.
[0303] The difference between the example of the wireless device
described in FIG. 21 and the example of the wireless device in FIG.
27 is that, in FIG. 21, the processors 102 and 202 and the memories
104 and 204 are separated, in the example of FIG. 27, the
processors 102 and 202 include the memories 104 and 204. That is,
the processor and the memory may constitute one chipset.
[0304] FIG. 28 shows another example of a wireless device applied
to the present specification. The wireless device may be
implemented in various forms according to a use-case/service.
[0305] Referring to FIG. 28, wireless devices 100 and 200 may
correspond to the wireless devices 100 and 200 of FIG. 21 and may
be configured by various elements, components, units/portions,
and/or modules. For example, each of the wireless devices 100 and
200 may include a communication unit 110, a control unit 120, a
memory unit 130, and additional components 140. The communication
unit may include a communication circuit 112 and transceiver(s)
114. For example, the communication circuit 112 may include the one
or more processors 102 and 202 and/or the one or more memories 104
and 204 of FIG. 21. For example, the transceiver(s) 114 may include
the one or more transceivers 106 and 206 and/or the one or more
antennas 108 and 208 of FIG. 21. The control unit 120 is
electrically connected to the communication unit 110, the memory
130, and the additional components 140 and controls overall
operation of the wireless devices. For example, the control unit
120 may control an electric/mechanical operation of the wireless
device based on programs/code/commands/information stored in the
memory unit 130. In addition, the control unit 120 may transmit the
information stored in the memory unit 130 to the exterior (e.g.,
other communication devices) via the communication unit 110 through
a wireless/wired interface or store, in the memory unit 130,
information received through the wireless/wired interface from the
exterior (e.g., other communication devices) via the communication
unit 110.
[0306] The additional components 140 may be variously configured
according to types of wireless devices. For example, the additional
components 140 may include at least one of a power unit/battery,
input/output (I/O) unit, a driving unit, and a computing unit. The
wireless device may be implemented in the form of, without being
limited to, the robot (100a of FIG. 30), the vehicles (100b-1 and
100b-2 of FIG. 30), the XR device (100c of FIG. 30), the hand-held
device (100d of FIG. 30), the home appliance (100e of FIG. 30), the
IoT device (100f of FIG. 30), a digital broadcast terminal, a
hologram device, a public safety device, an MTC device, a medicine
device, a fintech device (or a finance device), a security device,
a climate/environment device, the AI server/device (400 of FIG.
30), the BSs (200 of FIG. 30), a network node, etc. The wireless
device may be used in a mobile or fixed place according to a
use-example/service.
[0307] In FIG. 28, the entirety of the various elements,
components, units/portions, and/or modules in the wireless devices
100 and 200 may be connected to each other through a wired
interface or at least a part thereof may be wirelessly connected
through the communication unit 110. For example, in each of the
wireless devices 100 and 200, the control unit 120 and the
communication unit 110 may be connected by wire and the control
unit 120 and first units (e.g., 130 and 140) may be wirelessly
connected through the communication unit 110. In addition, each
element, component, unit/portion, and/or module within the wireless
devices 100 and 200 may further include one or more elements. For
example, the control unit 120 may be configured by a set of one or
more processors. For example, the control unit 120 may be
configured by a set of a communication control processor, an
application processor, an Electronic Control Unit (ECU), a
graphical processing unit, and a memory control processor. For
another example, the memory 130 may be configured by a Random
Access Memory (RAM), a Dynamic RAM (DRAM), a Read Only Memory
(ROM)), a flash memory, a volatile memory, a non-volatile memory,
and/or a combination thereof.
[0308] FIG. 29 illustrates a hand-held device applied to the
present specification. The hand-held device may include a
smartphone, a smartpad, a wearable device (e.g., a smartwatch or a
smartglasses), or a portable computer (e.g., a notebook). The
hand-held device may be referred to as a mobile station (MS), a
user terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber
Station (SS), an Advanced Mobile Station (AMS), or a Wireless
Terminal (WT).
[0309] Referring to FIG. 29, a hand-held device 100 may include an
antenna unit 108, a communication unit 110, a control unit 120, a
memory unit 130, a power supply unit 140a, an interface unit 140b,
and an I/O unit 140c. The antenna unit 108 may be configured as a
part of the communication unit 110. Blocks 110 to 130/140a to 140c
respective correspond to the blocks 110 to 130/140 of FIG. 28.
[0310] The communication unit 110 may transmit and receive signals
(e.g., data and control signals) to and from other wireless devices
or BSs. The control unit 120 may perform various operations by
controlling constituent elements of the hand-held device 100. The
control unit 120 may include an Application Processor (AP). The
memory unit 130 may store data/parameters/programs/code/commands
needed to drive the hand-held device 100. In addition, the memory
unit 130 may store input/output data/information. The power supply
unit 140a may supply power to the hand-held device 100 and include
a wired/wireless charging circuit, a battery, etc. The interface
unit 140b may support connection of the hand-held device 100 to
other external devices. The interface unit 140b may include various
ports (e.g., an audio I/O port and a video I/O port) for connection
with external devices. The I/O unit 140c may input or output video
information/signals, audio information/signals, data, and/or
information input by a user. The I/O unit 140c may include a
camera, a microphone, a user input unit, a display unit 140d, a
speaker, and/or a haptic module.
[0311] For example, in the case of data communication, the I/O unit
140c may acquire information/signals (e.g., touch, text, voice,
images, or video) input by a user and the acquired
information/signals may be stored in the memory unit 130. The
communication unit 110 may convert the information/signals stored
in the memory into radio signals and transmit the converted radio
signals to other wireless devices directly or to a BS. In addition,
the communication unit 110 may receive radio signals from other
wireless devices or the BS and then restore the received radio
signals into original information/signals. The restored
information/signals may be stored in the memory unit 130 and may be
output as various types (e.g., text, voice, images, video, or
haptic) through the I/O unit 140c.
[0312] FIG. 30 illustrates a communication system 1 applied to the
present specification.
[0313] Referring to FIG. 30, a communication system 1 applied to
the present specification includes wireless devices, Base Stations
(BSs), and a network. Herein, the wireless devices represent
devices performing communication using Radio Access Technology
(RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may
be referred to as communication/radio/5G devices. The wireless
devices may include, without being limited to, a robot 100a,
vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a
hand-held device 100d, a home appliance 100e, an Internet of Things
(IoT) device 100f, and an Artificial Intelligence (AI)
device/server 400. For example, the vehicles may include a vehicle
having a wireless communication function, an autonomous vehicle,
and a vehicle capable of performing communication between vehicles.
Herein, the vehicles may include an Unmanned Aerial Vehicle (UAV)
(e.g., a drone). The XR device may include an Augmented Reality
(AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be
implemented in the form of a Head-Mounted Device (HIVID), a Head-Up
Display (HUD) mounted in a vehicle, a television, a smartphone, a
computer, a wearable device, a home appliance device, a digital
signage, a vehicle, a robot, etc. The hand-held device may include
a smartphone, a smartpad, a wearable device (e.g., a smartwatch or
a smartglasses), and a computer (e.g., a notebook). The home
appliance may include a TV, a refrigerator, and a washing machine.
The IoT device may include a sensor and a smartmeter. For example,
the BSs and the network may be implemented as wireless devices and
a specific wireless device 200a may operate as a BS/network node
with respect to other wireless devices.
[0314] The wireless devices 100a to 100f may be connected to the
network 300 via the BSs 200. An AI technology may be applied to the
wireless devices 100a to 100f and the wireless devices 100a to 100f
may be connected to the AI server 400 via the network 300. The
network 300 may be configured using a 3G network, a 4G (e.g., LTE)
network, or a 5G (e.g., NR) network. Although the wireless devices
100a to 100f may communicate with each other through the BSs
200/network 300, the wireless devices 100a to 100f may perform
direct communication (e.g., sidelink communication) with each other
without passing through the BSs/network. For example, the vehicles
100b-1 and 100b-2 may perform direct communication (e.g.
Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X)
communication). In addition, the IoT device (e.g., a sensor) may
perform direct communication with other IoT devices (e.g., sensors)
or other wireless devices 100a to 100f.
[0315] Wireless communication/connections 150a, 150b, or 150c may
be established between the wireless devices 100a to 100f/BS 200, or
BS 200/BS 200. Herein, the wireless communication/connections may
be established through various RATs (e.g., 5G NR) such as
uplink/downlink communication 150a, sidelink communication 150b
(or, D2D communication), or inter BS communication (e.g. relay,
Integrated Access Backhaul (IAB)). The wireless devices and the
BSs/the wireless devices may transmit/receive radio signals to/from
each other through the wireless communication/connections 150a and
150b. For example, the wireless communication/connections 150a and
150b may transmit/receive signals through various physical
channels. To this end, at least a part of various configuration
information configuring processes, various signal processing
processes (e.g., channel encoding/decoding,
modulation/demodulation, and resource mapping/demapping), and
resource allocating processes, for transmitting/receiving radio
signals, may be performed based on the various proposals of the
present disclosure.
[0316] Meanwhile, the NR supports multiple numerologies (or
subcarrier spacing (SCS)) for supporting diverse 5G services. For
example, if the SCS is 15 kHz, a wide area of the conventional
cellular bands may be supported. If the SCS is 30 kHz/60 kHz, a
dense-urban, lower latency, and wider carrier bandwidth is
supported. If the SCS is 60 kHz or higher, a bandwidth greater than
24.25 GHz is used in order to overcome phase noise.
[0317] An NR frequency band may be defined as a frequency range of
two types (FR1, FR2). Values of the frequency range may be changed.
For example, the frequency range of the two types (FR1, FR2) may be
as shown below in Table 7. For convenience of explanation, among
the frequency ranges that are used in an NR system, FR1 may mean a
"sub 6 GHz range", and FR2 may mean an "above 6 GHz range" and may
also be referred to as a millimeter wave (mmW).
TABLE-US-00008 TABLE 7 Frequency Range Corresponding frequency
Subcarrier Spacing designation range (SCS) FR1 450 MHz-6000 MHz 15,
30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz
[0318] As described above, the values of the frequency ranges in
the NR system may be changed. For example, as shown in Table 8
below, FR1 may include a band in the range of 410 MHz to 7125 MHz.
That is, FR1 may include a frequency band of at least 6 GHz (or
5850, 5900, 5925 MHz, and so on). For example, a frequency band of
at least 6 GHz (or 5850, 5900, 5925 MHz, and so on) included in FR1
may include an unlicensed band. The unlicensed band may be used for
diverse purposes, e.g., the unlicensed band for vehicle-specific
communication (e.g., automated driving).
TABLE-US-00009 TABLE 8 Frequency Range Corresponding frequency
Subcarrier Spacing designation range (SCS) FR1 410 MHz-7125 MHz 15,
30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz
[0319] FIG. 31 illustrates a vehicle or an autonomous vehicle
applicable to the present specification. The vehicle or autonomous
vehicle may be implemented by a mobile robot, a car, a train, a
manned/unmanned Aerial Vehicle (AV), a ship, etc.
[0320] Referring to FIG. 31, a vehicle or autonomous vehicle 100
may include an antenna unit 108, a communication unit 110, a
control unit 120, a driving unit 140a, a power supply unit 140b, a
sensor unit 140c, and an autonomous driving unit 140d. The antenna
unit 108 may be configured as a part of the communication unit 110.
The blocks 110/130/140a to 140d respectively correspond to the
blocks 110/130/140 of FIG. 28.
[0321] The communication unit 110 may transmit and receive signals
(e.g., data and control signals) to and from external devices such
as other vehicles, BSs (e.g., gNBs and road side units), and
servers. The control unit 120 may perform various operations by
controlling elements of the vehicle or the autonomous vehicle 100.
The control unit 120 may include an Electronic Control Unit (ECU).
The driving unit 140a may cause the vehicle or the autonomous
vehicle 100 to drive on a road. The driving unit 140a may include
an engine, a motor, a powertrain, a wheel, a brake, a steering
device, etc. The power supply unit 140b may supply power to the
vehicle or the autonomous vehicle 100 and include a wired/wireless
charging circuit, a battery, etc. The sensor unit 140c may acquire
a vehicle state, ambient environment information, user information,
etc. The sensor unit 140c may include an Inertial Measurement Unit
(IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a
slope sensor, a weight sensor, a heading sensor, a position module,
a vehicle forward/backward sensor, a battery sensor, a fuel sensor,
a tire sensor, a steering sensor, a temperature sensor, a humidity
sensor, an ultrasonic sensor, an illumination sensor, a pedal
position sensor, etc. The autonomous driving unit 140d may
implement technology for maintaining a lane on which a vehicle is
driving, technology for automatically adjusting speed, such as
adaptive cruise control, technology for autonomously driving along
a determined path, technology for driving by automatically setting
a path if a destination is set, and the like.
[0322] For example, the communication unit 110 may receive map
data, traffic information data, etc. from an external server. The
autonomous driving unit 140d may generate an autonomous driving
path and a driving plan from the obtained data. The control unit
120 may control the driving unit 140a such that the vehicle or the
autonomous vehicle 100 may move along the autonomous driving path
according to the driving plan (e.g., speed/direction control). In
the middle of autonomous driving, the communication unit 110 may
aperiodically/periodically acquire recent traffic information data
from the external server and acquire surrounding traffic
information data from neighboring vehicles. In the middle of
autonomous driving, the sensor unit 140c may obtain a vehicle state
and/or surrounding environment information. The autonomous driving
unit 140d may update the autonomous driving path and the driving
plan based on the newly obtained data/information. The
communication unit 110 may transfer information about a vehicle
position, the autonomous driving path, and/or the driving plan to
the external server. The external server may predict traffic
information data using AI technology, etc., based on the
information collected from vehicles or autonomous vehicles and
provide the predicted traffic information data to the vehicles or
the autonomous vehicles.
[0323] Claims disclosed in the present specification can be
combined in various ways. For example, technical features in method
claims of the present specification can be combined to be
implemented or performed in an apparatus, and technical features in
apparatus claims of the present specification can be combined to be
implemented or performed in a method. Further, technical features
in method claims and apparatus claims of the present specification
can be combined to be implemented or performed in an apparatus.
Further, technical features in method claims and apparatus claims
of the present specification can be combined to be implemented or
performed in a method.
* * * * *